Clipons

[PaulSmith]

Sorry for going off topic but...

...  because the wind pressure shifts from arm to arm just slightly tweaking the steering and knocking me off course.

If the wind pushing you around is affecting your steering, you are probably holding on to tight. Instead of holding onto the bike to fight the wind, just go with it. As an excercise, you could try practising takeing one hand off the bars at a time and feeling how the rest of your body reacts. When the rest of your body barely notices, then the wind wont bother you.