Quote Originally Posted by MDHillSlug View Post
Probably, but I was told that I would need an MTB RD and STI shifters are not compatible with an MTB RD. Do you know if this is correct?
I'm pretty certain that's not correct. The push pull distances between road & mountain bike shifters are the same - derailleurs don't really care, they just do what the shifters tell them to do as long as they're big enough to cover the tooth range.

http://www.sheldonbrown.com/harris/k7.html

Scroll down to the 10 speed section and they go over using the shimano 10 speed with road shifters & a mountain bike cassette. People have been using shimano road shifters with IRD cassettes (11-32 & 34) with mountain bike rear derailleurs for years - SRAM cassettes are also fully compatible - so you can use shimano road shifters with the 10 speed large cassettes from SRAM (you should check into whether you'd have to use a shimano rear derailleur though, I know for a while the amount of push pull needed for a shimano rear derailleur was different than for an sram - so you had to keep the shifters & rear derailleur the same, but could interchange the cassette without a problem)

So you don't have to go to SRAM to get the bigger gear range - Alot of people seem to like the doubletap system though, I hadn't tried it