I tried both FMF series on mine, they worked pretty good. That Gnarly really does sign off quick.........brutal off idle /low end torque though. I ended up with a PC Works. Powerband seems to be like exactly what your looking for. I use my bike for everything from lugging on tight trails to MX racing, works great for anything you can throw at it. If you have to run an FMF I'd definitely go with the Desert version, very good pipes.
I run the V-Force 2 reedcage, with reeds set at high tension setting, 10mm reed spacer, thin metal head gasket, KIPS mod, ignition set on full advance mark,VP C12 fuel, Mobil1 2T syn at 80:1 and Iridium plug 1 notch cooler than OEM.
I'm curious to hear others chime in with which set-up is best on their bike.