The Evo was relegated to non-American countries for the first decade of its life. Americans could look at pictures of them in magazines, but never get a chance to touch the real thing. Then the Subaru Impreza WRX came along, and it was a hit. Mitsubishi saw this and realized there was room in the American market for a sport rally car, and they happened to make one of the best and lowest priced.
These cars are sold with I4 engines, with DOHC and turbocharged, of course. There are a variety of transmissions that have been paired with these engines, the top being the 6 speed twin-clutch gearbox, made for those people who really like to drive and only available from 2007 onward.
Although the Evo VIII, IX, and X are the only Evolution cars sold in the United States, many of the Evo I, Evo II, Evo III, Evo IV, Evo V, Evo VI, and Evo VII models were imported here.
These cars are just showing up on the used car market, and they are pretty hot. The best place to buy a used Evo is on eBay. There are also plenty of parts on there, if you want to fix one up or mod and customize one.