You create however many aux sends as you need in the DAW and route them to the ADAT outputs which you then access via the line outputs of something like Behringers ADA8200.
There will be latency involved, and slightly more than with a digital console (or RME's Totalmix) because if the run into the computer and back, but it's not usually a problem.
With the audient setup, is that all you would need as well in order to get all your monitors etc all connected up?
Yes. I think Audient have some helpful setup videos on their site. And download the user manual as that includes setup suggestions too.