One thing that was really nice about the DSA retro set was the adaptability of the set choices. That's crucial for me - I'm only doing custom layouts so if I can't get a full set of 1.5 width keys, I'm not interested. DSA retro GB included:
- alpha set included home keys for qwerty, dvorak, and colemak and single width \ key (retro kit 1)
- modifiers set included 1.25 and 1.5 width ctrl, alpha, caps lock, 1.75 shift (retro kit 2 & 3)
- separate modifier kits for 1.0, 1.25, and 1.5 widths include all the keys you need in custom layouts like ergodox (alt, return, shift, backspace, etc) (retro kit 7, 8 and 9).
- blanks in various sizes (1, 1.5, 2 width) and colors
So I'd vote for just repeating the DSA retro kit group buy scheme with a change in colors. Prices were reasonable and the flexibility means more people might be willing to buy in.