Glenn - The Surgeon action would be a fine platform to build an F/TR rig from, no worries there. Likewise your NXS should work just fine too.
I'm not a fan of extra long barrels, especially when one is not limited to a particular bullet like the old Sierra Palma 155 (#2155) which was only adaquate for 1,000 yard use and the reason longer barrels came into fashion in the first place, to eke out a few more FPS to stay supersonic to 1,000. I have no difficulty at all reaching 1,000 with the 155 Scenars or 155.5 Bergers with a 26" or 28" barrel. I also use medium Palma taper for my two F/TR rifles (.223 and .308) and they hold up fine through a 15 or 20 round string. The other things about the heavier barrels is the weight has to be taken into account for a weight limited class, the balance of the rifle may be a little fore end heavy for most some stocks, and they cost more once you get past 26".
Nothing wrong with your stock choice, personally I prefer a dressed out A-5 (fore end rail, adjustable cheek piece, 3-way butt plate) but that's just me. I would certainly recommend getting behind whatever stock(s) you are looking at before you drop the money on one to see if you like the feel.