Sorry you're going through this 27. I think we can all relate to some extant, and an adverse reaction or revision is something we all think about a little. "Experienced surgeon" is heavily emphasized here and for good reason. They all have great results.
I would emphasize seeing an experienced HR surgeon before assuming THR is the only option. Gross is obviously very familiar with the Cormet, plus he's got tons of experience. You might poke around on Pat's list of surgeons here and see who might be closest to you. That might not matter that much though. Lots of folks travel to get the best, again for good reason.
B.I.L.L has had problems for awhile, he posts a lot on Metal Ions section. You might just PM him and see what his thoughts are.
On the topic of waking up wondering what you got. In your case, it sounds like that really might happen because of the possible complications. For the average OA-ground down hip with a really experienced surgeon the patient will most likely have a lot of confidence, as will the surgeon, about the fact that they will be getting HR and not THR. With that in mind, I do think you should still be seeking revision to HR. The BHR install manual has a section on revision of the cup and I believe the cup is often responsible for adverse reactions due to a high angle. I suspect the Cormet has the same.
Good luck.