Do you have any plans for your display? also why the older Motherboard? This one is a bit newer and seems to cost about the same.
the DAC's look OK, however i'd still want to test them in a Car to make sure they don't have any bad habits while on alternator power.

what about storage and OS?
how much have you planned out?
what type of Car and what other equipment? Inquiring minds want to know....