Boy this thread has it all.... highlights the worst internet communication has to offer.
Most competent smith's should have the capacity to make a shouldered prefit from a tennon print, that's kinda the whole point of these kind of actions.
In theory a prefit was to speed the process of building a custom eliminating the need to ship the rifle. In theory it will work that way, except for the supply issues we're all dealing with. It's been stated earlier in the thread, the issue is solid supply of barrels. My shaft supplier sells big volume stainless barrel steel and said last week it's getting better but it's still horrid compared to 3 years ago.
Right now the fastest will be whomever has the closest access to a barrel blank that you want. If that's a prefit company, then great but lri or any traditional smith will win if they have the barrel in hand. It's probably worth looking for a blank from the myriad of suppliers and barrel companies to see what is close to what you want in stock, then start shopping prefit and traditional smiths.