Need a new bar that fits (or bar and new stem), new brake levers that are compatable with your brakes, brake cable set, a roll of bar tape, plugs for the end of the bars if wanted; that is about it. Oh and tools to make it all happen if you are currently tool-less - Probably just a combo metric hex key set is all you need.

I won't ask why as the bike seems better the way it is that with droopies on it...but to each his own
/K