I bought some drop bar ends for my flat bar. Very comfy. See this thread for a pic of my bike.
http://www.bikeforums.net/showthread...zed-Crosstrail
Nashbar does sell brake levers for the application, cheap price too. If you chose to buy a drop handlebar for your neck/stem clamp that fits and you buy the cheap brake levers, your shifters will not make it around the drop bar curves, they will snap. Also you may need to buy longer brake cables as the levers will be further away from the original spot on your flat bar.
So either do it like me and buy the 20.00 drop bar ends on ebay and that's it. Or buy the brake levers as well as the drop bar ends and thats it, (now you are up to around 60.00) or buy a new drop bar and also spend at least 100.00+ on a pair of brake/shifter combos. Now your into a little money.
Me? I bought the drop bar ends and thats it. Aside from a rigid fork swap, I will save the rest of the money for a real road bike if I choose to.
Good luck!!