think really hard about adding a .223
Another great alternative. Different enough from the 7mm-08 to open up some interesting opportunities.
That would be my option, too.
1:8" twist .223 would give him everything from small game to Whitetail/Pronghorn if he so desired as well as some great varmint hunting and out around 600yd target shooting if he were to have a sporter length barrel.
Ed