crosseyed: Try Fischer Clock timed games with a bonus of 1 to 2 days. I've found these limits move along and yet also give you time off when needed. Fast players move fast and it doesn't matter. Slower players will still need to make 8 moves in 10 days with these limits over the course of the game and will also be able to miss a few days.

Someting like this:
3 to 5 day start, 7 to 15 day maximum, and bonus of 1 day 6 hours.