You might like a KTM 380? Still a 5 speed but it'll pull tall gears easily.
We have a 2002 380SX, the power is unreal. I raced a 360SX back then, alot of bike too, but the thing ate kickers and their gears. They can be modded to be reliable though. All of them are pretty cheap these days. The 2002 has a 2009 shock and the original 48mm forks brought up to 2011 OC tech with revalves and they work better than my 2011 Husaberg stock or my upgraded 2007 SXf did.
Finding one street legal isn't hard either.
And, yes, they vibrate, but I'd rather try to tame one than build up a KDX!