For the gloves check out either some weightlifting or bike gloves. Local Walmart or Targets usually carry some. You can also search for tactical gloves online. As for the gun, simple rule is know your con. A lot of cons don't allow Airsoft in their rules but it all really depends on security. Some cons are super crazy on banning the airsoft others are more relaxed. What I tend to do for cons is use a full rubber training gun like
I simply bought a magnum black sharpie to color all but the tip black so it'd look better in photos. Sharpie rubbed of a bit on the gloves/hands but I just touched it up in between shoots and stuff. Since it's full rubber and has zero moving parts I've never had issues dealing with con security.