hey man, welcome to the sport, a couple good barrels for you would be the j&j ceramic, or a teardrop, or all american... they're cheap and work fairly well... you want to look for a 12, 14, or at the most 16" barrel, but 12 or 14" is most peoples preferences... and about the sniping thing, try and give this a read first
Snipers in Paintball
hopefully that helped, again, welcome to the sport, and have fun!