Well, there are no silly questions about this topic, it's too complex......when you're jumping in first time, anyway.
You've got plenty of spare storage so that's good. In your case, then, I'd advise you not to use Compression when asked by the image creation process. It's one of the main sources of image failures. Example: a disk (of any size) with 10GB of stuff on it will result in an image of about 5GB under medium / normal compression. But you hardly need to worry about that, so opt for zero compression, it's safer.
Testing the image can only be done by installing it. The proof of the pudding. You 'verify' it after creating it but it can still easily fail, believe me. But you've got a problem there, huh, a 64-bit image to be tested. That'll teach you to go out on the bleeding edge eh?
One solution is get another disk for your laptop. All the best ones have slide-out disks, it's about the #1 option to look for. I've got a Dell and although I wouldn't buy one of their PCs (as they aren't PCs), the laptops are good - and mine has a slide-out disk even though it's just a mid-range machine. Try yours.
ps - turn it off first
