I have a small affair booked for this Thursday night, three hours or so of dinner music. Today the client calls me up and asks if the performance can be recorded. "Sure", I say.

My setup is just a PSR-3000 going into a Motion-Sound PA-80 speaker/amp.

Basically, I need some way to record this Thursday night that
1) Will work with my current setup (give or take wires and connectors)
2) Will record in stereo and with at least half-decent audio quality
3) Will not be a major expense (most of the modern, digital field recorders seem to be in the $200+ range)
4) Will be in my hands by Thursday.... (best would be something I could readily buy locally, but if need be I will order online Tuesday with 2nd-day shipping)

The best I can come up with is the Sony Pressman® Portable Cassette Recorder TCS-30D. However I cannot really tell whether or not the mic-in jack will properly handle a line coming from the PSR (say, from the headphone jack, or a split from the main line out) or a line coming from my amp (it has an XLR-out but I have a wide variety of adapters so I could probably "convert" it to a small mic-jack size). Does anyone know if this will work?

Thanks for your help!