Do you already have a Rem action ? Rem actions are not that straight forward. Sloppy machining, skew and tapered threads, non floating bolt head etc etc. With a Savage action, you can screw in the barrel, set the head space and start shooting. With a Remington, the receiver almost always needs work, if you have a good local smith, he will accurize it for about $250. Then generally the barrel tenon needs to be custom made for the receiver since it will be oversize.
Thats basically the reason why the market for Rem prefits is so small. OTOH, if you get a stiller or similar custom action, they are precision machined, don't need any accurizing and will all take the same size barrel tenon. Thats what the custom rifle builders are generally doing...