WL;
Neither cartridge is actually well suited to C+C bullets, if you are stuck hard on C+C bullets then go to the heaviest in either caliber, in order to get enough SD to get penetration. Now you have changed the playing field and the big 7 will outshine the WSM when using heavy for cal bullets. I would recommend 175 gn in the big 7 and at least 200 in the WSM, the recoil will be more and the big 7 will now give significantly more velocity because of it's ability to hold more slower powder and the bullet encroaches less into the powder capacity of the case. The WSMs were designed with our much better constructed lighter bullets in mind, they will kill and give trajectories very similar to their larger belted cousins, but do it with lighter homogenous or super tough bonded premium bullets. For C+C bullet use it's hard to replace bullet weight and powder capacity. Hence given your very specific parameters, I'd have to advise you to use the big 7 and 175 gn C+C bullet about 2900 fps and you shouldn't get any nasty surpizes.
If you could see your way clear to use Nos Parts then load up 160s in the 7 and 165s in the WSM and you won't be able to tell them apart in any hunting scenario.