You could use all Blizzard cards like the Blizzard 1260, 1220/4, 1230 and even a 1240 desktop version from DCE. Other cards like Blizzard 1240T(ower) version and the Blizzard PPC cards don't fit in without heavy modification of your A1200 like putting in a tower.
If you could get a Blizzard 1240 desktop or 1260 version, then you need a beefier PSU like the lightweight A500 PSU version.
There is a memory expansion from Blizzard 1200/4. It looks the same as a 1220/4, but without a 020@28 Mhz processor on it.
