Hey there,
I suggest, if you haven't already, skip the Sony DAT. It is the best format out there for what you want, but it is expensive and is not supported by Sony anymore. I would use a Nomad 3 HD recorder or a laptop computer. However, that being said, the DAT is the best, as you end up with tapes of the show immediately afterwards that can be stored. Any type of HD recorder will require you burn the data to disc, and that may not be feasible on tour.
Also, running an AUD rig takes some doing, at least some monitoring. If anything, you want someone there to make sure no one messes with it. I would suggest offering free tickets to any tapers that would come out and tape if you want this. The Breakfast does this, as well as I'm sure a few others bands.
OK, for your actual taping, I would run a SBD. It is easy and most of the time, the soundman can monitor output levels for you (take 2 seconds). I would just run the RCA outputs (R and L) into the 1/8" analog input of the DAT or JB3. Makes usable tapes, simple, nothing else need excpet a $2 radioshack cable.
If you want actual GOOD tapes, you'll need someone to monitor, etc. You'll need a taper/archivist/groupie. But the SBDs will give you a good idea of your playing. Only problem with SBDs is they don't give an accurate rep of your sound, vocals will be extra loud, drums may be nonexistant, bass really low, etc. - the SBD is mixed for the room acoustics, not your tape.
Sucks I missed you last March at the Pour House, we could have talked about this more.
Terry
PS. A local guitar player just about always runs a MD and Sony ECM mic onstage with him. He gets crappy tapes he says, but he can hear what they were doing and it helps him write, etc...