You might want to set a budget, including both what you will spend for the space, and what you are willing to pay the designer. That will give you an idea as you look at available services.
You will also want to let prospective designers know whether you are talking about a bottom up reworking of the space, and purchase of equipment etc, or a redo of things like carpet, waiting areas etc.
There are quite a few colleges in your area. If you want a designer who might charge less you might put up an ad in the fine art or design departments and see if you get any interest. Though of course, you probably won’t want to hire someone without some experience.
When I had my space I did it all myself, as there were other things on which I preferred to spend money. And design services tend not to be cheap. I do know people who have been able to do some bartering for services. Of course, it depends, again, on how much you need doing. If you are talking about an all out redesign with flooring, equipment, permits to be pulled for more substantial work…. well, you probably want to think out the budget and get someone with experience.