CAAD 10 Build Idea

I think your target weight is a little optimistic, especially with a cheaper wheelset.
Even with FFWD F6Cs and Dura Ace this. 105 that .. assorted carbon bits.. yes a tad heavy FSA crankset.. but it struggles to pull the handheld digital scales down to 7.4kg.
Not all about weight of course, you have a super stiff race ready frame that wont squirm under power sprinting or uphill.
I was lucky to get the frameset a while back for £500... and a first build actually cost me just £800 .. but I re used a lot bits from my bike bits emporium.
This is the bike in race trim, though.

This is what you potentially need, and probably your cheapest solution:
http://wheelsmfg.com/bb-30-shims-shimano.html

This is a new option I haven't seen before - looks a lot better quality than the Derlin cups, as no adapters:
http://wheelsmfg.com/bb30-to-outboard-bottom-bracket-for-24mm-cranks-shi...

You also get Sleeves like this, that are often glued in:
http://www.jensonusa.com/FSA-Press-In-Adaptor-For-BB30

I'm running a shimano crank on a Caad10 using a praxis conversion bb (http://praxiscycles.com/conversion-bb/). They have the rep for being the best solution mechanically as they don't concentrate all the pedalling input on a small adaptor (though mine is creaking a little). Were it my build I'd save a bit on stem/bars and put it toward slightly better wheels, but looks good - Caad10s are ace.

I should add if you want to avoid the dreaded BB30 creaking, as well as the loctite you really need to get the bearings and adapter cups pressed in properly with a bearing press tool. Worth noting if you are planning on building up yourself, as I imagine not many home mechanics will have a bearing press. I always got this bit done on my CAAD at my LBS for this reason.

Yeah 105 cranks can be fitted, but an adapter needs pressed into the bearings to "size down" the BB30 to the 24mm diameter of the Shimano crank spindle. I've heard good things about the ones from Wheels Manufacturing, but like all BB30 bottom brackets it will be prone to creaking if not sealed up with a healthy dose of loctite. The nice thing about BB30 is you can always go smaller with adapters- it's impossible of course to go the other way. Basically means you can fit almost any crankset if the correct adapter is purchased.

If you want to go BB30 native and get the full supposed benefits of the BB30 system, you'd need a BB30 crankset. SRAM supports BB30, and Campag have just recently announced their new "Over Torque" crank spec that has the requisite 30mm spindle. Not sure if this has made its way to retailers yet, or on which groups. Shimano of course don't support and these days typically seem reluctant to go for standards that weren't invented in-house. There are options from FSA too, the Gossamer is probably the 105 equivalent but last time I looked these were a little on the pricey side as an aftermarket fit. Some people really have it in for the FSA cranks, my old CAAD10 was 105 with this crankset, I also have a Kinesis with the 105 cranks. There really is nothing to choose between them performance wise, and if they fit your budget they avoid the need for adapter cups.

If you are prepared to buy 2nd hand you can pick up Mavic Krysiums for the price of the Aksiums. I did....
And they are awesome.

Some stunning CAAD10 builds on weight weenies, check them out, it's a great looking frame. I would build it with Ultegra however.

+1 for 11 speed. If you can bear to, wait until the autumn, when the new Shimano stuff comes out, then either get the new 11 speed 105, or even a bargain on Ultegra 6800.
Even if you stick with 10 speed 105, it'll probably hugely drop in price when the new comes out, as well.
But beyond that it sounds like a cracking set up, the CAAD10 is a gorgeous frame to ride.

I'm willing to be corrected, but as far as I've found you need an adapter to use a Shimano chainset with a BB30. I don't know how good they are these days, but I've certainly heard that they're prone to getting a bit squeaky.

That sounds like it'd be a brilliant bike. If I were you, I'd try and throw a wee bit more at the wheels, but Aksiums are still very good.

The big thing is the BB30 bottom bracket - if you're getting a cheap 105 groupset online then don't forget you'll need an adapter or (ideally) a BB30 chainset. That's something you may need to put into your budget.

Oh, and I had an Antares saddle and it didn't work for me at all. That's totally personal preference though.

I'd be tempted to dig out a little more money and future proof yourself by going 11 speed straight away.

http://www.probikekit.co.uk/cycling-groupsets/shimano-ultegra-6800-11-sp...