I dont think you have to look for IMG friendly residency programs in PM&R. I applied to most of the residencies outside of NY and CA(about 50) and had probably 40+ invites as a USIMG. Do a rotation, get letters of rec refering to your interest in PM&R, and score better on the MLEs than the average US applicants and you will have alot of options.
Good Luck
PS-call the programs and speak with the residency secretaries, they will give you an idea. Colorado and Washington basically told me not to bother applying(I did anyway and did not get an interview).
PSS-Read Dr. Cuts thread under international section on maximizing the match for alot of great insights on successfully matching as a USIMG.