For another option, maybe take a look at have it chambered in 7mm Blaser Mag. It has a tick more case capacity than the 7 Rem mag, Norma brass that is available and pretty easy to get, Redding dies and they are easily available too.
I had Defensive Edge Rifles build me one last fall. Used a LA Rem 700, Hart #4 finished at 26 inches and topped it off with a NF 5.5-22x50. Shawn gave it his +P throat design. Currently shooting RL26, 180 Bergers, and using 215M's. That load produces right at 3050fps out of a 26in. tube, shoots in the .3's relatively easy and using one of their brakes, recoil is VERY minimal.
IMO, the larger cases like the 28 Nosler and 7 RUM need a 28in tube to really start to shine. If you want to stay in the 26 inch range something like the 7mm Blaser mag will run right with them but with considerably less powder.