Tire size after mini tub

Is 28" plenty tall Or should I look at going taller? Also I see a major price difference between the Bias ply and radial. What are the pros and cons of bias ply?

I think that if you go any taller you are going to have issues with the tire hitting the front of the wheel well. With a 28" tall tire and 3.89 gears I am turning about 2,900 at 60 mph.