the F4i powerband is much friendlier than the newer 600sFinding an F4 or F4i that hasn't been thrashed is a bit difficult; I've been looking for one. Also, the inline-4 power-band isn't great for street riding. No power/torque below 8000rpm then you get all of it in the space of 2000rpm.
If I were the OP, I'd be looking for a Kawasaki Ninja 650, Suzuki SV650S, or CBR650F. If they're open to naked bikes, I'd add the CB650F, SV650, and Yamaha FZ-07.
cough, cough.

