You can also pick up the excess ones that come out of Japan with low low miles for a good pirce but from what I have heard it is a painful and difficult road to go down (if anyone disagrees please let me know because I was considering this option until recently!).
I bought one of the jap motors about 6 months ago. The car runs great and the motor is strong. We had never swapped a motor before and got the book, took some of the stuff off the old and put on the new, change timing belt, seals, water pump, etc. A week from the arrive date it was in and running great.