I installed the National Cycle VStream sport touring version. Huge difference over stock in noise and buffeting. I'm 5'9", have the seat on the low option and had the stock screen on the highest setting. I have the VStream on the lowest setting, and it's perfect.
I also installed Pazzo shorty levers on both sides. Much more comfortable and easier to manipulate. I find I can easily cover both the brake and clutch with no exertion.
Two easy, high quality upgrades.