You are perhaps aware that eating insects, dogs, snakes and rats is pretty popular in China, Vietnam and Korea and in one Chinese province also cats are standard food. http://factsanddetails.com/china.php?itemid=146&catid=11&subcatid=73
Though I would never eat cats or dogs, out of a feeling of empathy with those beautiful creatures I wonder what do you know about the nutritional value (meat quality, omega 3 and the like) of these and other exotic foods from a Western perspective. I mean foods from animal sources that are not meat from cow, lamb, pig or sheep, nor seafood or poultry. Also whether you know of places where these exotics could be bought. Are they available at the China-towns of New York or San Francisco?
As for a resource, you can buy lots of exotic meats from these guys (e.g., rattlesnake, turtle, kangaroo, alligator):
No rats, cats, or dogs, though - they have an Asian Specialty section, but it appears to be empty.
Consuming the liver of carnivores like dogs and cats has been known to lead to vitamin A overdose (the famous example being polar bear liver), and apparently some Arctic explorers overdosed on sled dog liver. I wonder if this is, in part, why eating carnivores is considered treif and haram.
I strongly recommend against reading the Wikipedia article on dog meat if you like dogs.
Getting snake is fairly easy in the US...rattlesnake is one of the more commonly available exotic meats. Reptile meat like snake, alligator, turtle, etc. is fairly low-fat and tends to taste similar to poultry.
I was conversing with a company via email and asked if they could sell me unflavored roasted crickets (they usually just make flavored ones like BBQ or make it in candy) in bulk. They said they could do that for me, and then they asked me if this was for a restaurant business, and I responded that it was for personal use and then they never emailed me back. I'm kind of disappointed.
Crickets are supposedly a good source of protein, with a little fat and some carbs.
Per 100g, 13g protein, 6g fat, and 5g carbs.
Here you can buy horse, rabbit and emu right in the regular grocery store. There is a "chinese fondu" (I have no idea why fondu, weird french translation mistake I think) section with all kinds of hard-to-read labels, but you can usually find some unusual treasures in there (goose is my fav, not super crazy, but usually not easy to find). In my experience, between two different china towns in two different cities, you are not going to find dog or cat. It is not a big seller, North Americans would be disgusted. You can find all sorts of dried seafood, duck, and goose usually. I've never seen rat anywhere, except in the cage in my apartment where my boys live :)