Interesting.., although likely to blow well past my budget.
The alps switch, costar stabilizer style is also used on the Solidtek/DSI ASK-6600U, but its keycaps are sucky-- big-L enter, poor finish quality.
I think the trick on this sort of project would be to sell only one or two variants-- even if it means, say, ANSI and ISO overlapping keys-- to maximize economies of scale for everyone.