damn, is that all your own personal gear? you've got quit a rig there.
use a.pack (comes with dvd sp i think) to turn the 6 channels of audio into your preferred surround format. i'm not sure about bringing it back into fcp at that point, but final cut can certainly run 6 tracks of audio layered (though i don't know if they can be sent to discrete channels w/in fcp).
i purchased a motu 828mkii and i've got dp4 for doing surround work synced to video (i wish i could afford a protools surround setup, i used to use pro tools le and its still my favorite daw but dp seems to be more in my range right now, and has all the features i need - excellent surround tools). i have yet to get my surround speakers, though. what are you using? i bought and returned a set of klipsch promedia 5.1 ultras to test out the surround features, but i intend to get some active monitors and a sub when i can drop the money. i was looking at krk and event, but every time i commence researching the variety out there i have a hard time deciding. i may just get something like the m-audio lx4 for starting out, since i don't really foresee getting any monetary return on my investment for a while.
i've been interested in the dvx100a, what do you think of it? are you using the film gamma feature along with the 24p mode? i haven't compared 24p to 30p, but a friend of mine used to have a little jvc dv matchbox camera and the 30p video captured with it was beautiful (even with only 1 ccd). the only thing that concerns me on the dvx is the limited zoom. i wish it was at least 16x or so. have you compared the dvx to any of the other higher-end cameras? it looks like it still beats out the new xl2.
sorry to hijack your thread a bit, you've got an excellent sounding production setup (i'm jealous!)
- d