How about an "alphabet" progressive. Could have 20-24 teams, all have to have players last names start with their letter. Players first choice in draft determines their letter (ie Babe Ruth goes first, all players on that team have to have last names starting with "R"). Next season worst record drafts first etc.
Some letter would be combined: eg. I, Q, U, X, Z would be tough to fill - could also use first names (eg. Xavier Nady or Quilvio Veras, Ichiro etc.). Could go with 20 teams and combine I-J, Q-R, U-V, W-X, Y-Z.
I've played around with this making up teams -- would be competitive. Ideally also a cap to keep it fair eg. 120 M.