Well, good news... the Cone carts worked fine, flawlessly! I filled them up with Paul's simplified C-6 set up, and used the Epson driver. The first nozzle check I'd give about a 95%, did the maximum allowed three head cleanings, and after the third one I got a 100% nozzle check. The carts were recognized right away, and the Epson driver graphic showed all six carts as full.
Ran a test print, was a little disappointed but I'm sure it's because I chose an Epson Matt paper and I was using Premier Art FineArt. It was rather flat, poor DMax. Any suggestions how to improve my print with the Epson driver and non-Epson paper? I'll have to migrate soon to QTR. Got some ink blotches too but I've experienced those before, they usually clear up by themselves. The main thing is the Cone carts were recognized right away. They fit the slots more easily, too.
I mailed my MIS carts back, at their request, and they're going to test them in their 1400.
What a relief, thanks everyone for all your suggestions and moral support.
Paul