If you really want cheap power, lose weight. For every 8 lbs you shave off your truck (or you) you typically free up 1 hp. Get some light weight rims and tires and not only will your mpg increase but so will your acceleration and braking power because of reduction in rotational mass. I know this isn't practical for an off road vehicle but if your 4R is a paved road only warrior it's something to consider.
Are the offsets the same? I will have to keep my eyes open for a set of those.