IMO, Flankers should be fine, but only the early versions, 'cause the MiG-29 and early Su-27 were pretty much on equal ground. The F-16 should be allowed as well, seeing as how it's not nearly as 'new' as either. Nationality-wise, I don't see a problem if your character isn't flying an aircraft that doesn't match up with their nationality. I was under the impression that this was a (albeit elite) cobbled together unit given whatever planes they had to spare, thus the emphasis on Gen 3 - Gen 4 aircraft. 

Anyway, I added my second character to my initial post. For what it's worth, she's a ground-attack pilot specializing in SEAD flying the AMX International AMX (Brazilian variant)

EDIT: Yeah, definitely head of the Rafale that shot down the F-22. I heard of stuff such as Singaporean F-16s defeating USAF F-15s simply because the USAF pilots had been listening on RSAF comms throughout the exercise, and when our pilots switched to our mangled form of English known as Singlish, they got confused.

EDIT2: And to clarify, I had Everett take the MiG because it would be what was most familiar after having flown the Shenyang J-11, which is a copy of the Su-27. If I could, I would have had Everett fly an upgraded Su-27M or Su-27S