Well it is pretty difficult to say a 90 on the COMLEX = 220 on the USMLE...they are different tests of different lengths. I myself scored much better on the COMLEX than the USMLE and the opposite happened to 2 of my friends...
As for residencies in EM there have been numerous posts regarding this. Allopathic residencies are by far the more competative and have the better applicants. Classes are larger and teaching comes from board certified EM docs. It is far more strictly regulated by the Residency Review Committee, requiring research/academic project, strict lecture requirements per week and numerous other requirements. It is difficult to go wrong with any of the allopathic programs...and quite honestly, if you want to go DO ONLY, then choose a dually accredited program.
I for one, am going allopathic as are at least 4 other of my friends entering EM.
Also, do NOT choose the EM/FP stuff that some DO programs offer...you are putting yourself at jeopardy with such a program.