No, it works fine with SF. You will get a range of opinions on IO devices but, for now, why not just use the built in IO and focus on amplification and speakers.
Metric Halo. Apogee, and MOTU make reasonable IO devices. I've used M-Audio FW410, Yamaha 01x and MOTU 828 Hybrid units. Of those, the MOTU would be my choice but the preamps are a bit noisy (if you care). The Yamaha is powerful, but not supported. The FW410 is ancient and does not survive being put to sleep (the MOTU does).
Honestly, for using just EigenD, the optical output that is built in is fine and, hey, you already have it. I've used this quite a lot from a Mac Pro to a Yamaha Recvr to a pair of Klipshorns... that fills any room.
cheers, m