I'm not seeing how a threadless stem is going to help the OP with his problem. They don't seem to bring the bars up that much higher than a quill stem.

How about changing the stem to something shorter like a 90mm to bring the bars closer, and change those deep drop bars to something with a shallower drop? The seat looks awfully high to. Maybe you can bring that down some? The problem here just might be the fit of the bike with the these components and set-up. Maybe a good LBS could help you get a better fit and make you more comfortable