Which hop up bucking should i get?

i have an agm 614/416 and i need a new hop up bucking, i plan to upgrade the whole gun, ill be getting a 550 mm jbu 6.01 tightbore, and a silencer on the end, i may get a whole new metal 1 peice hop up chamber, but i was wondering which hop up i should get and which bucking, and nub, i want a 1 piece full metal hop up thats $30 or less, and a great bucking and nub