What's up dudes? Thanks for the amazing feedback!

I made a pilgrimage to the three LBS's in my area just minutes before work today.

The guy at Bikes Unlimited told me that if the stem was too high, the tube would collapse on itself... mmhmmm I'm not taking this thing off any major jumps or anything....
The guy at Bike Beat was totally cool, but didn't have anything in stock.
The guy at Spoke 'N True was just as confused about the inner diameter as I was and thought there was only one size. BUT he had a stem riser that I can fit my original stem into. 15 bucks. Right up my alley. So I bought that and we'll see how that goes tomorrow. It seems like I'll need a really long allen wrench which I'm pretty sure I don't have. Will I need longer brake cables?

fanks all.