Just got back from "lunch" at the LBS. I hauled in my GT, told them my idea, asked if I was crazy, and then went ahead with it. They recommended a Surly fork to replace my suspension fork (I think it's an Instigator, since I don't see any other suspension-corrected forks on their site), so I went ahead and had them order it. They've got loads of stems and tires that should work, so I'll be taking it back in next week (when the fork shows up) for the "upgrade" and a tune-up.