I disagree with T-Mar and roccobike slightly, having owned both 8-sp Dura Ace and 8-sp 600 "tricolor,"
at the same time, both STI and both full groups.

Hubs: Dura Ace
Crankset: 600
FD: wash
RD: Dura Ace
Calipers: 600 (also available in dual pivots)
Shifters: 600.
Basically the same as the DA, but mine were simply smoother.
I doubt there was much difference besides cosmetics.
Cassette: DA with the Ti cogs

The BIG difference for me was the compatibility issue.
I could run the 600 with other stuff, even ran it with a Campy wheel/cassette.

The DA was a PITA and rebelled every time I erred by going outside the box.

If you can get the full group, and won't have to worry about compatibility, get the DA, maybe get a spare RD.
You probably won't find hoods for either; they share the same hood and it's nearly impossible to find.

Either way, you're good, but my pick is the 600 "tricolor."