Barrel, revo, regulator, then nitro
Here we go with another formulated repeat post of what priorities for new guns are. I swear I've written it a hundred times, and I'm by no means alone in that.
First priority is a good barrel. CP, DYE, BOA, J&J, Armson, S/M (found only at
www.hanta-force.com/ai), and Lapco among others are all good choices; try them out and see which one works best for you. Don't get a barrel over 14" long. Just don't. Second priority is a good Revolution or Halo or Ricochet. Next after that you'll want a good regulator to keep your velocity consistent. WGP, ANS, Air America, and Palmer regs are all good for such. Finally you'll want to get a nitrogen system, which not only will be great for your gun now but also for any gun you're going to get in the future.
Have fun!