Gregg,
Flip4Mac is available for the Mac to create High-Quality Windows Media Files.
It cost $99 but it is well worth it.
For Sound Editing, you might try PEAK.
I have experience with Tascam Digital Mixers but not the DA-88…. but the process is the same.
Tascam sends 8 tracks out of it’s digital interface. The best interface I have used for Tascam digital audio is the MOTU 2408. I use it with Digital performer but FCP5 should see this interface. With the 2408, you can import up to 32 tracks of Tascam Digital Audio at once.
Hope this helps.