I built up the board (well, all but the regulator, which I'm still waiting on...) and fired it up by injecting the 5V through the "current" header. I was able to sort through about a dozen or so EPM7128SLC84 and even a few EPM7160SLC84 devices.  All from eBay, and 5/12 had locked-out JTAG :-(  But, better to learn this now, instead of after being soldered onto my project PCB!