Both my leagues are top 6. First 2 teams get a bye Week 1 in the playoffs the other 4 teams play each. The two winners of that game play the top two teams coming off the bye on week 15. Winners of week 15 play in the Superbowl Week 16.
We avoid going to Week 17 because most teams unless they are wild card rest their star players. The above I believe is the most common and most fair. The top 2 teams should always have a bye in the playoffs because they clinched the spot.
Furthermore, I'm not sure who the commish is but I have lots of widely accepted ideas for next years league. I'd even take the commish role if need be.