Sorry, I considered it "giant" because it's about 40% bigger than the computers at Best Buy. And it weighs proportionately more so it's a clumsy thing to handle. I didn't mean to be misleading.
I'm not worried about the hard drives really, I think they're pretty robust as long as they aren't spinning. I'm concerned mostly with the CPU cooler, which is one of the oversized type that sticks way up and looks like it would crack it's motherboard mountings with a good jolt. And also the graphics card, which is pretty much the same problem. I'm going to have the machine situated on it's side during transport for sure so they're sticking up rather than out sideways to help lessen the side-loading.
The wooden-crate idea is good, if I can make one light enough to handle. Most of the stuff I make of wood turns out grossly-overbuilt for some reason. If that fails I'll probably end up just dropping the $400 on the case.
Don't have the original box any more, and I just wouldn't be comfortable with only a blanket protecting my precious baby. It also has to share the back of a Civic hatchback with a folding table, monitors and several peripherals, so a hard case would also allow me to stack stuff on top of it.
Thanks all for the input! Now to the drawing-board.