Honestly, I think the M2 should be brought back into production, possibly with some cost optimizations (make it snap together instead of screw together, possibly, although there's durability concerns there). It's a buckling spring, with real buckling spring feel, that's built like a cheap rubber dome. Even with the lack of NKRO, I think it'd make a great entry-level mechanical keyboard. Then, step up to a Model F if you want better feel, more flexibility, and NKRO. (In this idea, I wouldn't continue production of regular Model Ms, as they'd take economies of scale away from the M2 and F. M2 for low-cost ($50-75), F variants for premium (think $150-350).)
Really, if Unicomp would just get on the Elliptical, they could get in shape.
However, regarding an M2 SSK, it's likely not a practical design - the entire M2 design is based around having the controller in the area above the numpad.