I bought the same size as you're looking at for the same reason of the max load weight rating. I have the Nitto Terra Grapplers on 18 x 9 Motto Metal wheels. They perform perfectly and the ride is firm when aired up and soften up a bit when aired down (no camper).
Speedometer is off about 3 mph, noticeable at highway speeds 60-65+MPH..
If you don't have a spacer lift, the tire will rub on the air dam and inside fender skirt at certain flex spots. I trimmed a bit off the air dam and took a heat gun to the fender liner to create some more room. Not sure how the 8" rim will change sidewall flex compared to a 9 or 10" aftermarket rim. Get a Package deal and swap everything!! :) photo of setup:
