Just a clutch will do. The clutch will come with a new clutch disk, pressure plate, throw out bearing, and clutch alignment tool. Grease always helps. A new front bearing retainer is always a good idea. A new pilot bearing wouldn't be a bad idea, except you need a pilot bearing puller to get it out. It depends how much the car needs it, or how much you feel like doing.
I usually turn the flywheel when I change out a clutch. I don't know if crate motors come with them or not, but if your not using a new flywheel, you may consider having the one your reusing turned just to be safe. It's inexpensive to do and it's good insurance.
You should always machine the flywheel or change the face (depending on the type of flywheel you have) when you do the clutch. Otherwise the new one may not bed in correctly and you WILL have problems then. As someone said its cheap so while you have everything off/out might as well get it done.