Analog Mixer + An Audio Interface

[UneducatedWeasel]

I'm looking at eventually upgrading to a larger desk, as I currently use an 8 channel alesis desk (multimix usb). It's pretty obviously limited, but as I currently have only one mic, it does the job. I wan't to have between 8 and 10 mic inputs ideally, so that I could potentially record an entire band at the same time. Something like the mackie onyx, or 1642 (I think that is what it is called) or there is a soundcraft one which is far cheaper. The have analog trs outputs. What would I need, interface-wise, to this into a computer, on separate channels. I would mostly use the mics only, probably little line level stuff. As an interface, would a firewire one do the trick, or would I have to go down the PCI route? This is all speculative, as it will be a while before I do this. Gotta get a few more mics first :P

Ta for any advice that you can offer.