I decided to buy one of the Cherry G86-63400's off of Ebay. I know they use rubber domes, but I wanted a big matrix layout to play with, and 18x8 is about as big as they come. Here's the link:
http://www.ebay.com/itm/230896192563It was only $70 including shipping (he's asking $68, and I offered $57 so it would be an even $70 all together, and he accepted it. I probably could have offered less, but hey, it's a more than fair price for one new in the box). I then went over to Newegg and bought a Cherry G99-1779ZUB SPOS Accessory Kit (it has extra 1 x 2 and 2 x 2, Lens and Keybodies and Paper) for $23, plus another $4 for shipping. Everything should arrive next week, and for less than a $100, I have something that will keep me entertained for months, assuming I don't break things.
I think I'll try Colemak, a modified Maltron, and maybe a couple of other exotic types (plus QWERTY in a format similar to my TypeMatrix 2020, just to try it out with something I know). I will plop the number pad in the middle, though, to give me the widest possible hand separation. And I might put 1-2-3 on the top of the number pad rather than the bottom, like a phone. You know, all of the things normal people do when they get a new keyboard.

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