What ohms are you running? Wire gauge? I don't think you will be happy going to an RM2 from a tugboat. RM2 is mainly for single coils, and has a small air hole. The RM4 is an Atomic clone, RM5 is a Zenith clone I believe or might be a Double Cross clone and the RM6 is a Stillare clone.
Blems are hit and miss on the website, best bet for a blem is to PM Redeyedancer.