Should I go with a 70# rig and back it off or should I get a 60# back it down to 55#'s and work up to a 63# max?
I'd go with the 60#, I'm not sure what you are planning on using it for though. If it isfor whitetails, you'll have plenty of "umph" to ge the job done. Performance wise, a 50-60# pound bow set at 60#'s will perform better then a 60-70# set at 60#'s. That is in theory anyways.