Who should we regard as role models?

From AN 4.159

This body comes into being through conceit. And yet it is by relying on conceit that conceit is to be abandoned.' Thus was it said. And in reference to what was it said? There is the case, sister, where a monk hears, 'The monk named such-and-such, they say, through the ending of the fermentations, has entered & remains in the fermentation-free awareness-release & discernment-release, having known & realized them for himself in the here & now.' The thought occurs to him, 'The monk named such-and-such, they say, through the ending of the fermentations, has entered & remains in the fermentation-free awareness-release & discernment-release, having known & realized them for himself in the here & now. Then why not me?' Then he eventually abandons conceit, having relied on conceit. 'This body comes into being through conceit. And yet it is by relying on conceit that conceit is to be abandoned.' Thus was it said, and in reference to this was it said.

I think that "conceit" includes comparing oneself to someone else -- I am worse, I am equal, I am better, I could be equal, and so on, see for example How are 'conceit' and 'identity-view' not the same?

But the quote above suggests that maybe it is not a "who" (a role model, a person) but is a "what", to be regarded as exemplary -- i.e. it's the practice ("the ending of fermentations").

See also SN 6.2 -- not because one is "more consummate than others", but because the dhamma is "to be known individually / by oneself".

I think this is only a partial answer to your question, a half an answer, see also SN 45.2 -- see also AN 8.54:

And what is meant by admirable friendship? There is the case where a lay person, in whatever town or village he may dwell, spends time with householders or householders' sons, young or old, who are advanced in virtue. He talks with them, engages them in discussions. He emulates consummate conviction in those who are consummate in conviction, consummate virtue in those who are consummate in virtue, consummate generosity in those who are consummate in generosity, and consummate discernment in those who are consummate in discernment. This is called admirable friendship.

Role models exist for when we reach their level.

Otherwise, for example, if you use an Arahant as a role model, you may end up disparaging & reviling stream-enterers, once-returners & non-returners, which will lead to your rebirth in hell and particularly rebirth in the animal kingdom of dumb beasts.

The key advantage in making the Buddha your role model is that although the Buddha is not living amongst us, his Radiance is present in the Cosmos, in the form of Cosmic Energy. When we pay homage through Buddhanusati, we're linking up with that Cosmic Energy. It is extremely powerful. Many faith based religions survive purely on such devotion. The Buddha however stressed the need to couple Faith or Shraddha, with the rest of the 5 x faculties i.e Shraddha, Veeriya, Sati, Samadhi, Panna.

In my opinion, keep only Buddha as your role model otherwise you will be in for a dissapontmemt. The next option is to keep any other teacher who is passed away without any known bad publicity. It is not advisable to keep any other living teacher as your role model. However, you can keep any living Kalyanamitta (spiritual friend) as your role model. The reason being you can accept any drawbacks of your spiritual friend as you know they are not perfect.

Honored Buddhaparisada, Good Householder Isira Ratnayake, interested,

Those wishing to follow the path of liberation, the path of the Noble One, seek for Arahats as there foremost refuge, headed by the Sublime Buddha.

'Indeed, the Blessed One is worthy & rightly self-awakened, consummate in knowledge & conduct, well-gone, an expert with regard to the world, unexcelled as a trainer for those people fit to be tamed, the Teacher of divine & human beings, awakened, blessed.'

The Savaka Sangha consits as the living refuge, those who have followed straight.

'The Sangha of the Blessed One's disciples who have practiced well... who have practiced straight-forwardly... who have practiced methodically... who have practiced masterfully — in other words, the four types of noble disciples when taken as pairs, the eight when taken as individual types — they are the Sangha of the Blessed One's disciples: worthy of gifts, worthy of hospitality, worthy of offerings, worthy of respect, the unexcelled field of merit for the world.'

Usually people took and take Refuge in the Community of Monks, after their master himself.

If it is proper to take a certain person or a Bhikkhuni, or a woman as a men, as near model?

Some points to consider:

• Seeking Refuge in Individuals as perceived as perfect, bears the danger of missperception and so it's especially for those not having joined the Sainthood better to stay at the Sangha as field of merits, seeing ones chosen particular guide in times of sacrifices within or after them.
• Refuge in woman might be often accompanied with defiled thought, yet not necessary so. How ever, good if always seeking for the foremost.
• Turning toward another gender bears a lot of danger and so was even at the Buddhas time the the very near guidiance total unusual and seperated. Althought the female Sangha was bound after the male, they had to look after the refined under their "own kind".
• A mixed gender relation for a intensive student and teacher relation is even not something praised for children and parent, the lesser free of many dangers for a spiritual, yet there might be seldom exceptions where all works out benefical and of course a wise and decerning person can benefit from all.

If a woman seeks for intensive training she does good and is encouraged to seek after a female near teacher, one who has the higher and foremost as refuge herself, and guides on also to the monks. What isn't good is to seek after a group or person who stands in conflict and opposition of formal hierarchies and is better to be avoided for the most cases. People with problems with hierarchies, even with gender respect problems are heavy ensnared in Sakayaditthi, pride "better am I, worst am I, equal am I"

While Vinaya, conduct, way of life, as foundation of Dhamma, should be seeks to gain under same kind, in regard of teachings of mind-matters, Dhamma, one does good to seek out for Arahats, at least Noble ones, regardless of Gender.

So since the "relation" between layperson and Monastics focuses most more on Dhamma, there is really problem to take a good Bhikkhuni as foremost model in regard of taught as long as living in proper dependency and still in different modes of live.

The have been even ex-husbands seeking for Dhamma, to gain path, from their former wives and Bhikkhunis appear often as great advicers in the texts for (mostly singe) lay people.

May it be of help to straighten the importand things out.

Possible extended answer and given space for discussion and deeper investigation can be found here.

(Note that this isn't given for trade, exchange, stacks and what binds here, but for escape from this wheel)