OP- the best suggestion I have is to watch videos of the rides on youtube. It may ruin the "magic" for you to see lights on versions of Rock n Roller Coaster or Space Mountain, but you'll have an idea of what the coasters really are and it will give you a decent idea of whether you think you can handle it. I'll echo the sentiment of another poster-- these coasters are nothing like what you'd see at Six Flags.
DH does not do coasters AT ALL, and I can't get enough of them. The coasters at Disney are just his speed, and even though they're not the big, scary coasters that I absolutely love, they are fun as heck to ride. There are no super huge drops other than at EE, and only one coaster has a flip (Rock n Roller Coaster). They are more curves and bunny hops than anything else. If you can handle the drop at Splash Mountain or the drop with Tower of Terror, I think you'll be fine on the coasters.