Well you asked, just bring money. He made two rifles for James_in_TN and he set two world records with the rifles. He is behind in work right now and not taking new orders until after June 2005 (maybe).
If you do get into a custom gun don't limit yourself to the 22-250 when there are so many great custom calibers to choose from. Yep, you will probably have to reload for it but that is where the other part of accuracy comes from.
Out of the factory box accuracy comes from Remington, Winchester, and Savage in standard price varmint guns. From the same maker you will find good, great, and exceptional accuracy. No two guns from the same maker are the same. Just like cars, you will find a lemon every once in a while.
You have an interesting choice ahead of you and lots of information to collect and sift through. Start with the catalog's and see what gun fits what you expect the gun to do. Then go to your favorite gun shop and heft the models you are interested in. How that gun feels in your hands is important.