300ex big bore/stroker

Looking for some input from anyone who has built 300ex motors. I have only personally built one motor for a friend, used an 83mm JE piston (352cc) resleeved cylinder, heavy duty rod, KW valves/springs CWR 420 lift cam, rockers, 36mm Mikuni round slide carb, white bros header and custom muffler, open airbox, 10k rpm rev box. This motor runs GREAT and is used as an mx machine, has awesome mid range-top end power. Now my question is, anyone know some options as far as stroker? id like to build a machine for myself using the same 83mm JE piston kit, adding a stroker and oversized intake/exhaust valves and probably a 39mm FCR or 38-40mm Lectron carb.

Can anyone point me in the right direction as far as a reliable company that can build a stroker crank for me?
Id like to have it done right, but I still realize this will probably be mostly a hand grenade. I'll be using a large oil cooler, air scoops and possibly a fan. Chassis will be fully built, 400ex front end, +3 swinger, gusset frame, etc. Should be a fun ride :)
Link to Cycleworks Racing

Some images of the quad that I built with the 352, mine should be similar.
http://i319.photobucket.com/albums/m...y/dsc00011.jpg

http://i319.photobucket.com/albums/m...y/dsc00012.jpg

http://i319.photobucket.com/albums/m...y/dsc00013.jpg

http://i319.photobucket.com/albums/m...y/dsc00014.jpg