Difficult - unlike other places, the UC's, which control many of the EM residencies, aren't very cosmopolitan - as a Californian, I'd say they can be surprisingly xenophobic/elitist. Maybe it comes from having the three tier UC/CSU/junior college system, and many immigrants. But if you're interested, you can certainly try, maybe they'll get tired of throwing good people out the front door.
In EM, I only know of SGU grads at Highland, and SGU and Ross at MLK/Drew, I think. Test scores were high, I'd imagine.
Only 2 out of 340 students matched in EM from Ross in this past NRMP. If you walk around campus here, you'll hear a large portion of the students say that they want to go EM. Right now, the odds are not in their favor.
A better bet is to do your IM residency, then do a fellowship in Critical Care medicine. You won't be cracking chests or doing a lot of trauma work with that, but most ED's are not Level I anyway.
Point is, you don't need to be Board Certified in EM to work in an ER. When I worked in a large, inner city ER years ago, only 2 of the 18 staff doctors were board certified EM. The rest were IM and other medicine specialities.
MS2 Ross University