Sounds like a fun swap. The more you shop, the better the prices are going to be. A junk yard donor would be good, just plan on having to go through it and buy the performance parts for that motor.

For a cruizer, you might want to consider Matt's suggestion on the stroker motor. To his list of parts I would also add a good set of aluminum heads. It might be a bit less money to rebuild what you have rather than buyin another motor, rebuilding it, then swapping things. If you want big cubes, less hassle, how about a 351 Windsor with a stroker kit and aluminum heads????

Anyway, like Pro said, it's gonna be a kewl ride, keep us updated on your progress.