http://www.fabcraft.com
I would use these folks, they are located in western Montana. I had them do some tunnel work on my sled and they do great work.
Whoever I chose I would want to help with the build from start to finish. I wouldn't want to take on a full custom build until I get some more knowledge under my belt. Mistakes can be expensive!!
2 stroke!! Brent Linderman would build the engine ,and CR racing would build the chassis.
4 stroke yammy!!!!!! Alpine motorsports would build the engine and CR racing would build the chassis.
Myself.
I've had a machine built once. I ended up rebuilding it myself. Too easy to throw thing together on a sled. At least you know its done to your standards, and you become intimate with the sled making any troubleshooting a breeze.
I supose it would depend on what your plans are.....full chassis, engine mods etc....or just simple bolt-ons....or turbo, lightweight parts etc...
IMO starting with any of the newer chassis, there is little need for much more than a few lightweight parts and a little more power to have a lightweight and reliable sled that will rival the $30,000 mod sleds of just a few years ago.
WINTER and 1200psi make killer IQR's
if you want a company ive been going to Fastrax for my build and their building some cool stuff and holz makes killer mountain sleds