Going with a 7-08 just because you already shoot a 7mm caliber rifle really may or may not make sense. You probably wont be shooting the same weight of bullets anyways, and switching to a .308 caliber of rifle will only set you back dies and different bullets, which you would probably have to buy anyways since your ultra mag is probably going to be using heavier bullets than the 7-08 anyhow. If you are buying a gun for your wife, I would have her hold and feel a few guns in either caliber and make your decision from there as to which one to get.