i love the UL but by the time u buy the barrel and some extra backs, youve got the price of like a new freak , ULs are nice, but J&J is still my fav. barrel company, cheap,light,accurate,quiet,not picky on paint
depends what kind of paint you get and how long you wanna keep your gun.
-if your on a budjet: SP teardrop or J&J Ceramic
-If its a temporary gun: same as above
-If you only shoot one kind of paint(ie, you only go to one field): get the dye since a barrel kit is pointless
-If you use a variety of paint get: the empire 7-piece, empire 5-piece or the evil kit depending on your money
i'm not such a fan of the empire kit. i think the bore sizes are too big... but it really depends on what paint you use. i have a bizerk kit with .685, .687 and .689 and those sizes are perfect.. except for zap sport, that stuff was too big, but it's bad paint anyway
edit: if it's worth mentioning partly why i got the smaller sizes is also cause i was annoyed at balls rollin outta my pump.. and the balls at the fields in my area seem particularly small so you should consider the size of the balls you're goin to be usin mostly.