Poserworld used to have the David freebie footie kit. Now it's just the M3 version in the downloads area, with additional fits available on the same page. The M3 fit is in the picture.

 

Also, PhilC has a free footie kit for Don (the P5 figure) in his freestuff archive.

I also have a footie kit for the G2 figures too, but can't find it listed at CP, I'm sure I got it there, but it may have been a bundle or freebie at one time.