Carl - have found out over the years that all too often yu can pay for a name. By far the most important thing is fitness for purpose / sizing. I would say then think about a good set of wheels and then groupset.
Here's a suggestion - give some dealers a bell who are, or have been racing cyclists. Moreover, those who know about time trailing and triathlon. There's a lot about who will ensure that you are fitted correctly on a frame that will do the job. They can, and do help people. Also, if you go to them their mechanics will always help you out.
Some names that come to mind are Brian Rourke and Dave Hinde. People like that have years of experience.
If you are convinced you want a Cannondale, its worthwhile getting it through such a dealer for these reasons.
Oh a biggy - custom paint jobs are nice to look at, but are often expensive and really dont make the thing any faster. Good luck in your quest.