Have you got clippon areo-bars fitted to your road bike?

If not try them first, adjust your seat further forward with a short sterm. not quit the same, helps alot. an with a nice light set of wheels and small ratio cassete (if you havent already 12-21 say)you would be far off, in the fun area.

Personally i wouldnt get a TT bike if your not going to race on it, due to the cost. But if money's no issue then go for it.