Bar ends won't give you any aerodynamic benefit really, and they're designed for climbing anyway. Best way to get you into a more road bike position is to swap your handlebar "stem" for a longer flatter one, preferrably a race model. This will physically increase the distance from saddle to handlebars and force into a more stretched position. It's also a very easy part swap to perform, won't take more than five mins.

I did this on my Trek 7300fx and it made the world of difference. Swapped the stock stem for a Bontrager Race version that has twice the horizontal extension. Not only ar my rides a little faster but they're more comfortable too.