First, I would recommend NOT getting 16" aftermarket wheels. Check tire prices and availability to see why.
I went through the same backspacing thing when I was looking at wheels. I also considered 2.5" backspacing. I finally decided against it because it just pushes too much of the weight outside of the hub and, in my opinion, is going to be just as harmful to the hubs and balljoints as running spacers with large tires. It will also push the tires out so far that you will have more issues with rubbing on the outer edge of the wheel wells.
If it wasn't for needing to rotate the wheels, I'd say 2.5" would be fine on the rear (or any solid axle for that matter) but on the IFS, it's just as bad as spacers with oversized tires.
I was told 4.25" backspacing was too much. I risked it, though, and all the naysayers were wrong. I don't have issues on the outer wheel wells because of the larger backspacing (although probably at the max) which pulls the wheels/tires inside the wheel wells more. From the pictures of everyone else's trimming with 33x12.5 tires, I didn't have to really do much more, if any more, trimming than them inside the wheel wells even with 35s.
So, short of it is, I would recommend an 8" wide wheel with backspacing between 3.5" to 4.25". Also, a 15" or 17" wheel for offroad tire choices/prices.