Road Cycling - New frame or new wheels

To help me keep on track in my weight loss attempt I am thinking about rewarding myself with a new carbon frame or a nice wheelset upon reaching my goal. I started riding again about 2 months ago at 235lbs and am currently at 220lbs. My goal is 190lbs by March. Also since I will turn 40 this summer I would like to do a 40K TT under 1 hour. I have come within 3 minutes before so I think it will be doable. I also would like to get back into racing. I have been off the bike for almost 8 years so I have a lot of work to do to get back in that kind of shape.

I have been on Cannondale since I first started riding about 15 years ago and currently have a nice CAAD 4 frame w/full Ultegra and 32/Open Pro wheels. I like the stiffnes of the Dale but as I get older I am looking for something a little more comftable. I am thinking about a Trek5200/5500, Kestrel Talon SL or maybe a Look 386i. I have not test ridden any carbons yet but just going on reviews.

My Ultegra/Open Pro wheels are fine but looking for something lighter and/or more aero. I estimate they weigh around 1900gr for the set. The current lightweight wheels seem to be in the 1500gr area. If the rims are all about 400grs how much of a difference will I notice if the weight savings are all in the hubs and spokes? Even at 190lbs I won't be a lightweight so what wheels that are light and aero that would hold up for me? Tubulars could be an option if I decide on a race only set.

So, what do you think I should do? A new cabon frame or a new wheelset?

Thanks for listening.

Hi,
I would go for the frame. I would also include Ti and steel. You can create a stiff ride with any material short of overcooked sphaghetti. So what you are actually looking for is a high performance design that makes a few concessions to comfort.
An alternative approach would be to set up the Cdale for TT; and get a whole new bike for training. That bike could be set up for speed AND comfort. A bike like the Jamis Quest would do the trick, or you can look at some of the great mid price bikes like Gunnar.

If you decide to go with the 5200/5500 you can have both. The Racelite wheels are a good strong , light set of wheels and they come standard. Personally I did the same thing, got a new bike as a reward. I went with the 5200 and love it. I just could not see getting a 5500, which was several hundred more, to get the same frame and "only" get Dura Ace components.
If you decide on wheels only Velomax makes some real light strong wheels. I think this may be my next "reward" for myself.