5+2 in the front and 2+5 in the rear is the optimal set up for stock suspension or the MTS Kit.
For a full LT Kit you want 5+2 on all 4 corners....
I normally recomend 5+2 offset on all 4 corners and then run 2" spacers on the rear only. So if you do get a LT Kit someday you can sale the rear spacers and you dont have to get new wheels...
But if you are getting a good deal then dont worry about it.... cross that bridge later if you get a LT Kit.