Sets will be modular. So you would buy BASE, a MOD PACK, and a PACK # to fill out the rest of your language keys. If one wanted they could buy whichever color they wanted from each of those 3 kits to build a full set. So if Dolch and Skidata won, you could do that. Or if you already had a Dolch set, you could just buy a set of Skidata mod pack.
All set will come with Alt AND Alt Gr as default as pretty much everything but US ANSI uses it. All the current proposed keys are listed in post 2.