Its great that AmigaKit ask the community about what they want.
My suggestions would be
1 Ram card
2 Accelorator card (68K)
3 Accelerator card with built in wireless network card (and cable to the a1200 expansion panel with socket and arial or built in like a laptop)
4 Conversion kit and instructions for people who want to install slim CD drives inside the 12oo case, including measurements, buffered IDE interface etc.
5 A600 accelorator (ok ok this is not for the 1200!)
6 Er.. is there any chance that Amigakit can licence old designs from companies that no longer make Amiga hardware?
7 would it be worthwhile being a reseller of the GVP hardware that has recently been re-released?
ok thats some quick ones, plus my first post ever.