Well, I've got my kit sorted.
Skink Pinhole Sets:
L39-mount and 218um pinhole for the Bessa L.
M42-mount and 280um pinhole for the EOS 3 and/or Spotmatic (and maybe the 7D for chimping on light-readings, because I'm lazy and ttl-meters don't like pinholes).
Maybe the Lensbaby pinhole/zoneplate optic on my EOS 3 Control Freak.
The M42 mount can take colour filters as well as tele/wide adapters (37mm filter ring + step ups). That means I can also fit it (via a filter ring and macro-reversal adapter) to my Kiev 88CM with a 380um hole (which has double-exposure capability, changeable backs, and just looks cool) or Kiev60 (which has WLF with sports-finder for framing), or Pentacon 6 (which has timer-release and the same WLF).
As for film, i'm probably going to use up some 120 Velvia that expired in 1991 and cross-process it, some long-dead Agfacolour, and/or some B+W (PanF50 and wait a few minutes maybe?). 135 film I've got way too much C41 that I don't use, maybe some B+W too...