If you end up having to travel, go to Dr. Cherry. He's really the most knowledgeable and skilled in the country. There's a number of people who have posted here (maybe in a different thread?) who have traveled across the country to have him do their surgery. In a best case scenario, he can point you to a vascular surgeon in Minnesota who trained under him at Mayo, then he would consult with that doc throughout the process. That's how mine went.

If you happen to have anyone in your cycling club who is a cardiologist, she/he could likely do the ABI you need. You don't want to have it done through your standard vascular ultrasound clinic, as the method they use to assess the exercise aspect of ABI, generally toe raises, is not sufficiently difficult to cause symptoms in athletes. That was ultimately how I got my ABI assessed -- a team member who was a cardiologist did it with me running on their office treadmill, although bringing your bike in with a stationary trainer would be better. As little red mentioned, that would be the test that would at least give you a pretty good idea if you're dealing with iliac artery endofibrosis. Of course, a CT angiogram would tell you as well, but it's about 100 times as expensive and can be less conclusive.

(Edited to apologize for repeating things that were already said by little red. I didn't read until after I posted) :)