I would ask around in terms of graphics cards just to be sure, mine causes no problems at all no spikes or issues, I have not had much luck with Nvidia and low DPC on this build (had to RMA it) or on my dell latitude E6520 (for work) with those cards DPC was around 200 microseconds so who knows it is hit or miss unless you just follow someone elses lead, just ask on every forum you can that way you avoid having to play detective yourself. The graphics card is by far the biggest issue in any DAW build we know the z68 chipset is fine for audio so I would not worry too much about that but graphics cards can really hurt your build if you choose the wrong one.
I love gigabyte boards mine is pretty awesome I plan to add SSD’s at some point and it has built in cooling that makes it very easy to keep the chipset and CPU cool very awesome stuff. the UD3 would be fine just be prepared to maybe need a ti firewire card in case the onboard wont play nice with your interface.