Stock maps are more than fine... Metro Conquest and Rush are both good meat grinders, Bazaar SMALL Conquest with 32 people is my favorite thing ever, rush is also very good on that map... Seine Conquest can be fun, I don't really like that map very much, much better with Rush. Damavand Rush is just awesome... I mean... base jumping. Kharg is meh, good for vehicles, same with Caspian Conquest... Caspian Rush is pretty fun, better with more people. Noshar and Tehran are ok, more vehicle maps though, ok with Rush... and Firestorm is good for vehicles.
Personally, I prefer infantry play (or stick me in the gunner seat of a helicopter)... but yeah, we have a ton of options with the stock maps.
EDIT: We can also do Squad Deathmatch, I need to win a round of that to get my L85... so we should definitely do that if we get 8 or more people.