I ended up winning an e-bay auction for a Jay Turser Classic 10 portable amp. It seems to have what I want except it only comes with 1 input jack. I'll report back when it comes in.

Now does anyone know of a cheap battery powered mini-mixer that can combine a mic input (low impedence XLR) and an instrument input (high impedance 1/4") and then plug into the amp input jack? Does it screw up the quality to use a XLR to 1/4" converter for the min into the amp?

JAB