Anything you buy in that price range is going to be a damned good bike. From what you say, you aren't in a position now to drain every poofteenth of performance out of the bike, so go with the one that fits you best and which tugs at your heart.
Be aware that carbon bikes (and parts) are non-repairable and damage from bingles comes from the inside - ie, you don't know it's breaking until it's broke. That means that a carbon bike is potentially less long lived than a mainly metal bike (because sooner or later you will crash it), but there's no evidence that carbon wears out more quickly and in a decent crash, you can write off any bike if you're unlucky.
The bling merchants and weight police will go into raptures over saving a milligram here and there, but think about it - you weigh 90 kg, how much bike weight do you need to save before it makes a significant impact on the TOTAL weight (bike and rider).
I don't think you need to go any higher than Ultegra components, but if you've got the money and don't mind spending it, Dura Ace is better. And don't forget to look at Campy gear either - many a love affair has been forged with Campy bit. But go for whatever floats your boat.
If you were a serious, front line racer the relative differences might be important but to be honest, for the rest of the world, the fit of the bike and your fitness and skill are more important. Of course, I can point you to forums where such a comment would be howled down as heresy
As I've said often enough for it to be my mantra - look long, think hard, then buy the bike you fall in love with.
Cheers
Richard