For the 139/140gr weights most of the powders from IMR-4350 thru RL-22 in burn rate can give exceptional accuracy and good velocity as well.
I know your probably looking to narrow that down a bit more, but in today's environment you might not be able to simply walk in somewhere and find exactly what your looking for.
The only 7mm Rem mag I have is in a Rem Sendero, and it has mainly shot the 162gr Hornady SPBT since I got it. I worked the load up using RL-19 and left well enough alone. With the groups hovering around an inch out to 300yds I never felt a need for anything else.
That said since I also acquired another Sendero chambered in 7 STW, I have been thinking hard on dropping the load for the standard model back to the lighter bullets and using the heavier ones in the bigger case. Just haven't gone there yet.
Going with one of the powders in between the above mentioned burn rates though i do not see how you could go wrong, especially with the 139/140'ish weight bullets.