Man, that is tough. A lot of moving parts.
Gunson is the best clinician I've ever come across. He can literally diagnose anything with precision. As far as surgery, I didn't have surgery with him, so I can't say, but I've seen some great cases in-person and some not so great cases in-person (he offered this person free revision, as of 2018, which was "owning it" and a good sign). I think he is a bit overworked, and I think he'd admit that to you if you asked. He really needs to find a partner.
I don't know much about Raffaini so I can't speak to him at all. The people here who have used him generally seem happy. I'd say if you can afford the 3k, take the trip. Otherwise, you will always wonder. Go with the guy you feel most comfortable with and who presents the plan that makes the most sense.
Regarding rhino, another tough call. I'd find Raffaini patients and ask their experience. There are some here. Maybe they'll chime in. Ask his credentials in rhino while on your consult, too. If he's not an expert, then maybe you're wise to parse it out to two different specialists. I'm not sure. Rhino terrifies me so I never looked too deeply into it. I can give you a guy I know is good in the States via PM. Agree the idea of traveling to Europe if there are complications sounds awful...that puts a damper on that option for me, so it's really up to you to figure that out and what you're willing to do.