18x10

Okay so im new here but i have been researching on getting new tires and rims on a 98 sr5 extended cab. I have a few options in mind but i also have a few questions. Ive looked around and just cant seem to find anyone running an 18x10 -24 offset with stock uca's. I have a 3" Front 2" rear leveling kit. Right now im running 265/70/16 on a stock toyota rim guessing its 7"(correct me if im wrong). I dont usually go rough wheeling but i do go off the beaten path occasionally. Im looking for a little bigger tire and a little wider. I have a trail gear pre runner front bumper so im not really worried about rubbing the front bumper but i might rub the cabside fender?

My questions are:

What backspace do i need to not rub the stock uca?
How wide of a tire can i go?
Would adding 1.25" wheel spacer keep it from rubbing the uca?
Would adding another 1-2" lift help?

here are the tire specs:
*backspace is 4.5 on all

315/60/18
Rim 18x10
32.9x12.4x18

305/60/18
Rim 18x10
32.4X12X18

295/65/18
18x10
33.1x11.6x18

285/65/18
18x10
32.6x11.2x18

285/65/17
17x10
32.8x11.2x17


I might go with a smaller rim size like 16x10 or 16x9 if i have to but whats your input on what would fit from experience or knowledge.

Thank you in advance for your help