(2720SL) 14 to 15 inch tires

I know that this is probably covered all over, but I can't find exactly what I want. I have a 2720SL. (Had blowout - lost plumbing)
I am going to get the lift kit and then upgrade to non-Goodyear 15 inch tires.
This will improve my load range.

Questions:
What is good brand of tires.
Can I go to the ST225/75 15's:
What is difference between 75D & 75R