there is alot of great builders out there, u should call and talk to some. word of mouth is good, but i like to talk to a builder direct and see what kind of portig they recommend.
with that, u need to know what kind of carbs and pipes are best for "their" port job.
i used jeff at f.a.s.t. on my 4 mil cub motor.
jeffs a very cool cat to deal with, and helped me set my bike up to full potential.