Looks like the answer is no, you can't use a different screen. If you look at the Droid 3, it appears to be the same, or similar LCD, but the flex cable that is attached to the LCD is different, and this wouldn't be something you could swap on your own.
Be careful with the replacement glass from ebay! I had bought a cheap one as well and after installing it, my buttons, as well as a small portion of the screen didn't respond to touch. My solution was to contact the seller, as the screen I received was plastic like (not guerrilla glass like the OEM screen)as it scratched super easy. I argued that they sold me a non OEM screen, and they happily sent a new one, that not only worked, but at least looks to be to be OEM. The giveaway was the foam gasket that the second screen came with, where the cheap one they sent me had none.