Thanks for your valuable input guys.
My current road bike is probably a little bit hefty (Orbea ??), so I thought I'd keep it for training, as the excess weight can only help during training, and then I'd really benefit when on a TT!
I was thinking more of a carbon frame, if only for the fact that they look drop dead gorgeous in comparison with anything else. That may well be the wrong reason, but....
I'm also toying with getting new wheels for my current bike, but having read countless threads on here, I am now totally confused. I'm 75kgs, not too fast, but making progress, so looking for wheels that will accommodate my getting stronger, if that helps with any suggestions. Clinchers, tubs, deep dish....no idea! 
I also live in the flatlands otherwise known as Norfolk, so plan on visiting the Peaks etc, for my Sunday long rides, to get more practice on hills! 