Hey there's a lot of confusion in the tuner world when it comes to offsey too you know. I still can't figure out what width and offset to put on my little project car.
As for the 15" or 16", generally the 16's are cheaper for a p metric tire over an LT tire. The 285/75/16 is a 33" tire. If you want a 31" tire for a 16" wheel get 265/60/16. 32" is 265/65/16.
I'm in the same boat a you. I'm looking to get 16" wheels and tires
Agh see the tire size calculator made those two sizes almost spec the same. I'll see what they have in the 32" size.
I just emailed my contacts so I haven't ordered yet.