Yea 5.38 is an all around good ratio, hints why everybody runs them. I'm not a one ton Guy or anything other than an 8" but that's what I would go with.
Shouldn't this thread be in general tech, or even 4x4 talk section???
But I agree, 5:38's are a good all around ratio....even 5:13's (little larger pinion) depending on the ratio in your t-cases...and general driving style.