I would add a comment to the head gasket thing- although it might seems like a big deal to someone new- I recommend taking a head off a new motor, and because there iISN'T a lot of care taken to their finishing at the factory- then taking a good flat metal file and lightly filing both surfaces on the head and on the motor piston jug- to a smooth shiney surface-
That helps the gasket do it's job by eliminating rough and diverse areas on the mating surfaces. It sounds like a lot but it's really just taking off the four bolts and then tightening them again with reasonable but not extreme tension.
It may keep you from having to do it later after blowing a head gasket trying to fill the not-very-smoothly-finished surfaces.
I like boygofast for price and no frills. He could have better descriptions on parts- most of them could. http://stores.ebay.com/BoyGoFast