Yiu could put a silencer or barrel extension tk hide extra length or you could just get the madbull 6.03 they are great barrels too and half the price.
You can get a lonex or guarder or madbull rubber as well here at airsoftparts.ca
He has or should have the madbull tightbores as well dont get 6.01 get 6.03 the 01 will be more headache then its worth in an aeg.
And yes promy barrel is prolly the best but they cost half the price of yer gun you can get just as good results for half the price with the madbull 6.03 as for the rubber buy one each of the lonex types and see wbat works best for you. I like soft rubbers in the cold and hard ones when its warm (in a 400 fps setup with. .30 bbs. Yer results may varry depending on velocities and bb weights. Most folks use soft they will be able to hop just about any weight at any velocity in most tempratures