We all have to weigh the risks verses pleasure. Like others have said, I won't knowingly see a provider that is known for CBJ. That being said, it isn't without risk.
I'm sure a lot of people wouldn't admit to the following, but since I don't use this site for references or connecting with providers, I'll come clean with an experience I had just a few years ago.
I was in Panama City a few years ago to help out a relative. Since I was there specifically to help this person, I only went out for entertainment one night. Long story, but before the evening was over, I got about a five minute blowjob (uncovered) in the parking lot of a small bar. She wasn't a sleazy chick either. Very well put together, a fitness enthusiast, she was impeccable from head to toe. A week later, I was at my doctors office being treated for Clamidia.
Guess I don't have much of a point to make here, but I have easily seen well over 500 women, with a whole lot of risky street play in my youth. I just found it amazing after so much play in a lifetime, I get my first STD from a quickie BJ in a parking lot. You never know when it's gonna happen.