Linus usually knows what he's on about, so before you do that, I would just say, since it should only take 15 minutes, disable and uninstall all your video drivers, then manually force on a currently known-good version. If that doesnt work, then yeah. Nuke it from orbit. I understand that's the only way to be sure.

EDIT: Oh, hey. You aren't running RAID are you?

Why thank you. I was just admiring your advice as well. I completely agree with nuking it from orbit once it can't be reliably saved. (I watched that again the other night for the umpteenth time - it's one of those movies that I rarely walk away from once I've accidentally watched a few minutes of it.)
Also - and I'm not questioning your competence here, it sounds like you're handling this really well - have you checked your cable connections? An intermittent black screen can mean that the contacts to the HD are not seated firmly. Windows can lock in black if it loses connections to the hard drive during POST or the system load. I know you've probably done this, but it doesn't hurt to ask. (Though it is weird that you have a cursor if this is the case, I don't clearly recall having any mouse control.)

One other thing, I was using 32 bit windows and I installed 64 bit on the new drive (I had been considering switching anyway). I went to setup for AMD, but it tells me that it was intended for 32 bit systems only. Would just deleting the file good enough? How do I manually force a currently-known-good version?

You'll need to use the same architecture (32 or 64 bit) as the operating system that boots and runs is using - otherwise, your addressing will be all wrong. Im typing on a phone so forgive my laziness here, but a tutorial is beyond me. If you google "manually install video card drivers" youll get like ten great hits right at once. The tldr version is: download driver suite from video card manufacturer. Uninstall any current video drivers. In the device manager, go to the video adapter that has the ! on it, and right click. Somewhere there will be the option to install the driver. Try that

Ya, I've checked them, but it never hurts to double check. There are variety of things that can cause this or something similar. Some people get a black screen, but are able to bring up task manager or msconfig, which would make it a lot easier, but no such luck for me.