If you are not planning on going really big power, I would check for a used engine out of a wrecked car.
Pumaspeed is another option if you want a new engine, though their communication is a bit lackluster. And hopefully they ship things better than they did for a used transmission they sent me: it was shipped loose in a doubled up cardboard box. Needless to say, parts of it were sticking out of the box by the time it got to me, installation is on Monday.