May be you want to look at rme's Babyface. Fantastically low latency and low cpu hit. It has ADAT in/out.
I use it for mixing / mastering with my notebook and professional monitor speakers, works great for me.
SW: C 7.5.10 /64 & Wavelab 8 on W7/64 & W8/64
HW: 2 x Dell Precision T5500 Xeon 12-core workstations
Audio: 4 x rme HDSPe / Multiface II, 3 x Octamic II
Surface: 3 x Avid MC Mix, 1 x MC Transport
Plugins: Audioease, Lexicon, Neve Portico, Yamaha Vintage, SlateDigital, Izotope