Ok, the score so far is:
1a: 4
1b: 6
2: 5
I'll put the names up in OP #2.
I've been doing this for a while, so I know that ten interested people can really mean five actual paying participants.  And since my goal is only to ensure I don't end up with a personal lifetime supply of giant PCBs, that is enough for the test buy.
So I will get some actual quotes for the case parts and then set up a lightning group buy for the proto kits.  Probably I will ask for five kit buyers and then let the rest of the first run go as bare PCBs.  I may set that up as soon as this weekend.
Also, a couple of notes re the case and keycaps:  I've been using this case and the WASD custom keycaps as my main home keyboard for about a week or so.  The first thing I find is that the case needs taller back feet, so I'll incorporate those into the cut-pattern for the existing parts.  Round stepped pyramids, probably.  The second thing is that the WASD keycaps are really attractive and have a good texture, but that MX Brown switches might not be the right match for them.  Well, not after spending the day banging away on an F-122, anyhow!  The switch/keycap combo is very light.  If you are a tappity-tappity touch-typist, they might be great for you.  I learned to type on computer terminals, so I need a heavier feel.  I shall experiment with other switches and springs.
Regardless, the WASD keycaps are still an open option at $65 directly from them.
TL;DR The proto buy is a go. First five as kits, with extra PCBs after that. The case gets taller rear feet, and the WASD keycaps are available direct from WASD.  Stay tuned.
 - Ron | samwisekoi
Auto-typed by my GH-122 keyboard.