There's a web site called Vetinfo.com and there's another one called Askthevet but not sure of the exact address. And Jan recently found a good one when her newly acquired iguana stopped eating. (Jan if you see this- let CatDad know ok?).
I use a ridiculously expensive vet but she specializes in cats and is up on all newest everything so I trust her. (The Feline Hospital- in Salem MA). Our vet visits aren't for just a few minutes, they are half an hour or more for just routine- I suppose I get my money's worth!
Maybe you could locate a vet that specializes in felines or call the Feline Hosp. for a connection- or I will if you want to go this route!!!
Does your cat vomit immediatly after eating? Is there a chance of eating too fast? (I get that here a lot). Or furballs? What are stools like? I know youv'e already checked for these things but I can't help but ask, I guess because it's not in your post. Did they check for lung worm (well, that causes coughing and vomitting so if no coughing then maybe not..). Eye worm?- known to the west coast but not the east coast and I can't remember the symptoms..Argh!! Keep us posted!