I'll 2nd Ghost on that. I use a Spyder...well 3 spyders techied into one and they are incredibly cheap, easy to work on, versatile and easily stripped, cleaned and serviced...they run on both Co2 and air (a godsend if you go to a site without air fills), parts and upgrades are really cheap and Kingman do EXCELLENT support from their website, with tech diagrams of most of their markers.
I use a Spyder Sonix (modified) with a turbulence bolt, expansion chamber, electra gripframe, 12" smart parts teardrop barrel and when using site RPS paint it's one of the most accurate markers i've ever fired.
If you consider the Spyder (see: "Budget") option though, make sure you get an electric frame model (Electra, AMG, Imagine e-99, Fenix, Pilot) it really makes all the difference..oh, and whack an eggy on top....most Spyders are capped at 13bps so you'll never outshoot it and chops will be avoided too.....
Here ends the Sermon of the Right Reverend Spyder-addict....