Ivans:

Maybe not ideal, but you can fit yourself and probably come pretty close.

http://www.shotgunreport.com/TechTech/TechnicalTracts/GunFitting.html

Follow the Technoid's instructions, measure the result and send the dimensions off to AyA or whoever, try to use a sxs (if that's what you're having built) for the self-fitting, the dynamics are a little different than the rest.

Bill