I did this conversion on my Cannondale. Here's what you'll need to do this on a reasonable budget:

Shimano 9 speed bar end shifters, since your bike is a 9 speed (I think):
http://jensonusa.com/store/product/S...+Shifters.aspx

A set of drop bars. I like Easton's offerings, and they're very cheap. To figure out the width of bars you'll need simply measure the tops of your shoulders from left to right (where the pointy bones are). I personally ride 40cm:
http://www.jensonusa.com/store/produ...+Road+Bar.aspx

A set of brake levers that are V-brake compatible:
http://www.jensonusa.com/store/produ...ke+Levers.aspx

Some bar tape. This is subjective, but I like Fizik:
http://www.jensonusa.com/store/produ...ebar+Tape.aspx

A set of cabling for your brakes and a set of cabling for your shifters (although the shifters will come with cabling, so you could use that):
http://www.jensonusa.com/store/produ...sing+Kits.aspx

Lastly, you can experiment with fit by using your stem as it is or removing and flipping it upside down. This is how I did mine, although this pic is very out of date:


Hope this helps.