I think the lineup looks great with either QB. Earlier this season, Griese lit up KC for 376 yards passing and 2 TD's and looked good last week despite throwing the game ending INT. Brooks, on the other hand, has been struggling the last 3 weeks, but Minn. is a great team to bounce back against (ranked 30th against the pass and 31st in passing TD's allowed ). Good luck.
Ditto what everyone else said. I think both QBs have excellent matchups and it would be hard to go wrong with either.
I'd actually lean towards Brooks of the two. The Saints are playing for playoff position while the Vikings "blew their wad" last week in a division game against the Pack.
The Chiefs (despite their bad defense - which has played better recently) are still in the running for a playoff berth and the Broncos are a division opponent.
So what I'm saying is that of all the teams, the Vikes have the least to play for, so I'd go with Brooks over Griese.