Here's a little something I concocted this afternoon.
Keep celebs/civilians. You could still get a few of the old-schoolers, and I think there's still enough recognizable names on the CBS shows, not to mention the cable channels owned by CBS.
First main game: traditional Pyramid, six categories, 7-in-30. Small bonus card, i.e. the 7-11
First bonus round: similar to the "words beginning with ___" tiebreaker, or the Double Trouble category from Davidson's version, 7-in-45. Each correct answer is worth $200, $10,000 for all 7.
Second main game: traditional Pyramid, switched teams, 7-in-30. Larger bonus card, i.e. the Mystery 7/Super 7/Big 7, just a larger prize.
Second bonus game: traditional Winner's Circle, worth $15,000. Layout as follows.
1000
500 500
200 200 200
Third main game: traditional Pyramid, returning champion vs. first game champ, blind draw for celeb partners. Only one main game, no bonus card, winner goes on to the final Winner's Circle, played for $25,000.
I suggest the first bonus game just to break the monotony of three Winner's Circles. Throw something new into the mix, but it could just as easily be a Winner's Circle. A total of $50,000 could be won, but that doesn't mean it has to be called The $50,000 Pyramid. CBS's daytime shows only allow for about 36-39 mins. of show, so I think you could spread things out nicely with this format. No rushing, and you can give the teams a chance to breath in-between each round.