This would give college football 13 postseason games per playoff for a total of 26. There are roughly 40 bowls right now. Go ahead and keep whatever bowls you'd like to bring that total up above 40 total postseason games and provide the NCAA, TV people, fans, and sponsors even more football games.
The NC playoff would include:
SEC champ
ACC champ
Big 12 champ
Big 10 champ
PAC champ
Two highest ranked G5 schools who are conference champions
5 at-large schools based on rankings
The NIT playoff would include:
SEC champ runner-up if not in NC playoff, if so then next highest ranked team
ACC champ runner-up if not in NC playoff, if so then next highest ranked team
Big 12 champ runner-up if not in NC playoff, if so then next highest ranked team
Big 10 champ runner-up if not in NC playoff, if so then next highest ranked team
PAC champ runner-up if not in NC playoff, if so then next highest ranked team
3rd and 4th highest ranked G5 schools who are conference champions if not in NC playoff, if so then next highest ranked G5 school
5 at-large schools based on rankings
This format guarantees four G5 schools with access to one of the playoffs and two that have a chance at the NC. By keeping it with a conference champion instead of just the highest ranked team it rewards the regular season and allows 4 of the 5 G5 conferences the chance to have a meaningful post-season.