I'm doing the same thing, trying my best to make my way through an enormous DAT collection [1k+], I was pretty lucky since I was able to do transfers without any real hardware cost, I still have my workhorse Fostex D5 -> Optical Cable -> (via Toslink) MacMini 1.83 GHz, Core 2 Duo, 2GB Memory (Snow Leopard 10.6.6), the key part to all of this is having a repeatable workflow... naming conventions, any mastering, source documentation, etc... having this stuff scripted *really* comes in handy.
I know *years* ago +sleepypedro had some batch files used in cooperation with some DDS drives to 'extract' the audio from the DAT's. Gives me an excuse to reach out to Peter, does anyone else have a way of doing that (i.e. DAT2WAV, etc.)?
Also.... I'd be happy to do any Widespread Panic / Related DAT transfers if you need 'em.