You can find a KA24DE (240SX motor) pretty easily; they were used in quite a few Nissans, such as the 240SX, the Altima, and the Pickup. If you want a JDM 240SX (180SX) engine, though, you'll have to pay at least $3000 to have it imported from Japan, and then more to have it swapped. My suggestion would be to ditch your JDM dreams (i.e. don't waste your time on sites like Batfa) until you're old and rich...just get an old 240SX or Civic, those cars are cheap and have huge aftermarkets.