The amount of work that you do on a Remington action would depend on what your intended use is and your accuracy goal. If you need a .308 for some definite reason, then stay with that, but these days, there are some interesting choices that you may want to pursue, if you are going with a new barrel. As far as a full house action treatment goes, I have a friend that has a custom barreled, well bedded 6BR (slow twist for varmint and BR bullets) that is amazing. Bob Brackney did the work. BTW a couple of years ago Bob won the Calif. State four gun title using all Remington actions that he had sleeved. This is not to say that the other smiths mentioned above could not do a fine job, it is just that, knowing Bob ,and his work, I have no need to look elsewhere for a Remington smith. If you will tell us more about what you intend to do with the finished rifle, we can give more specific advice. As has already been said, your biggest gain will come from a better barrel, and I will add, chamber design.