I don't think the Mr Right harness would work since the balls are rather long on the RM basic packer, plus they're not flat backed like the Mr Right.
I personally hold my RM basic packer in place by the shaft through a hole in an underwear waistband... It hasn't shown any sort of wear and/or tear.
Edit- Also, I love it as a packer and even though I admit it's on the heavy side, it's never bothered me. In fact, I had a problem with packers riding up on me and this one doesn't.