If you want accuracy, R-Hop or flat hop is definitely the way to go. You'll keep yourself busy for a long time with that. A barrel with high consistency also helps. My recommendations are Prometheus EDGI 6.03 (steel) and Madbull 6.03 (aluminum). Don't neglect your BB's. IMO it is the most important part of the equation.
To increase FPS, you'll need to improve air seal and system efficiency, and eventually work your way to the spring.
I won't go into too much detail. Here's a good read:
http://forums.airsoftmechanics.com/i...p?topic=6050.0