I found 2 sets of rims I really like my 2 questions are which is better 15" or 16"? and what's a better backspacing 3.25" or 3.62"? which one will cause less stress on my bearings and stuff? I plan on going with a 33x12.5

 

Get the 15s tires will be cheaper.

 

3.25 backspacing is ALOT. Most people Dont run more than 3.75 on an 8" wide rim. 4" backspacing would mean the mounting surface is centred in the wheel which would cause the least amount of stress on your ball joints. And I would go with a 15" rim.

 

would a 3.75" or 4" give me any problems rubbing anything other than fenders (which will be trimmed) I'm lifted 4.5" n looking to get 33x12.50 tires

 

Nope that should work. Just remember to bumpstop and adjust your steering stops. I have 3" lift on 33's with 15x8 wheels with 4" backspacing and I rubbed my long arms a little until I adjusted my steering stops.

 

I'd go with 3.75-4" backspacing. 3.25 will stick way out. And I prefer 15" wheels. I won't put bigger than 15's on my XJ.

 

What they all said.

The 4" will be a sweet spot on backspacing. 15" are way more desireable than 16". They are cheaper and have much more tire selection support for our kind of rigs. Usually people move bigger (usually 17") when they are going extra big tires, like 40s, or they need more clearance for brakes on bigger axles.