If you're leaning toward benchrest, look at what the competitors use.
Actions like the Stolle and Nesika Bay have been used in the benchrest game for a long, long time. But, that's only part of the solution. Another major consideration is the barrel; again, the cut-rifled offerings seem to have the edge--Obermeyer, Kreiger, and Bartlein. Shilen puts out an outstanding barrel, as does Hart. And, for a lower priced barrel, Douglas can also turn out good barrels.
As for the stocks, McMillan is the name I hear of the most on precision rifles. They will work with you--I was lucky enough to take a tour of their factory recently. They can make everything to a featherweight stock, to a bench model that has the same dimensions as a regular stock, but weighs over 40 lb! (Yes, I handled one, and it IS that heavy!!!)
The trigger, of course, has to be clean and consistent. I have heard some names mentioned in great triggers; Geisele, Timney, and Jewell. Savage has started making both good actions and good triggers to go with them.
The best advice I can give is to talk to folks like McMillan. They know how to make a rifle shoot.
While I was there, I saw the world's record benchrest target, hanging on their wall. It was shot by Gale McMillan, the founder of the company.
It measures .002. No, that's not a mistake or a typo. I think that they can point you in the right direction.
