First Timer Help

I've got a 2017 Longbed SR5. I'm finally throwing some new tires & rims on it with a 2.5in leveling kit. It's only a 2WD unfortunately, so I don't think it'd be worth it to get a gnarly suspension lift and what not given I'll be doing minimal/basic off roading. This is the first "mod" I've done to any car, so I have no idea what I'm doing.

After looking into it, here's what I'm thinking:

17in Black Rhino Chambers with Toyo ATIII 265/70/R17, which I believe is 31.5in.
OR
same rims, but instead with Firestone Destination P255/75/R17. I'm thinking this wouldn't kill the mpg as much and be a bit cheaper, but I'm not sure. Both have good reviews.

Current "problem" with the Black Rhinos is that they're only available in -18 or 0 offset. I think -18 could look nice, but don't know if this would cause any rub. I did the math and that would barely give 4.5" backspace on the ATIIIs, which I think is a rule by thumb around here.

To put this in question format: Which tires would be better (ACIII or Destination) and what offset would be best for either pair?

I've been doing tons of research, but can't seem to find the info I need, so if anyone could help out or point me in the right direction I'd really appreciate it. Thanks for any help.

 

@garfield4 the zero offset for sure, a -18 would poke out to much. Toyo has an outstanding reputation on the forum and is a more common size than the Firestone. Hope this helps.