Well..if you go out to specialized.com and look at the specs of each...

I would do the Dura-Ace/Ultegra build, just to keep it to one grouppo manufacturer. To be clear it is a mix of Dura-Ace and Ultegra.

The SRAM build has TRP (Tektro) brakes, and an Shimano Ultegra cassette, KMC Chain (not a bad thing)...with everything being a mix of Red/Force. I would get the dealer to swap casettes in this build.

And you know, a good dealer will swap parts out for you here and there....there will be cost considerations for you though. First and foremost, make sure you are fit properly. Don't be the guy who got so focused on the bike that that was the only thing he was looking at. Either of these two bikes are very nice race ready/level bikes.

I hope I am not being offensive, but based on the question and the way it was worded I get the impression that you are buying (or have it bought for you), and might be getting in a little over your head. I could be wrong though, who knows...