score:15
It's not a full answer, but if you're interested by medieval Arabic travels, the unavoidable reference is Ibn Baṭūṭah. In his Rihla, he describes three travels he made during the 14th century :
This text has been translated in many languages, so you probably can find a version in your preferred language. There is a French translation in la Pléïade, and a 19th French translation freely downloadable at the Université du Québec à Chicoutimi; I haven't found (yet) an English translation available on the web.
He mainly used the commercial routes, but he probably didn't to "the furthest extent of [Arabic] expeditions. According to the wikipedia page on spice trade, the route went as far East as Molucca.