A JG may be a bit hot for indoor out of the box, best to see if you can get it chrono'd beforehand. You don't necessarily need both an AEG and GBB. I've actually used a GBB for most of the night and did well. Use what you have and adapt.
As for gear, a good paintball mask will do well enough to protect your eyes and face. Gloves are strongly recommended as well. Just grab a pair of Mechanix gloves from Marks Work Warehouse or someplace similar. Keep in mind that we play with no mercy rules so don't be surprised when someone engages you from just a few feet away. Long sleeves should be the norm unless it's unbearably hot during the summer months. Expect to take home a couple of bleeders if you don't cover up.
Try and pick up some additional mags as well if you haven't already. Everyone will hear you coming with a hi-cap shaking like a maraca. Plus reloads in a firefight add to the realism factor.