I also lean colts too if I had a gun to my head. Especially with Mariota out and Gabbert in? I'm not putting money on Gabbert period. No play for me here but I think you have the right side.
I was in the same situation as you I wanted the Ravens + another on a teaser. Looked at the Chiefs and passed, big mistake (my gut instinct, OAK SUCKS), looked at the Rams and passed, mistake, SEA and passed that worked out and came up with either Minny or the Chargers. I ended up going Chargers but it was close, nearly went Minny, almost still got whacked but Rivers finally did something in the second half. I don't need to tell you how bad Cousins is because you're a good capper, you already know that. I won't put a dime on that guy in a big game, but you'd figure if Chi pulled starters he could make something happen. Rivers at the end of the season is similar but I trust him a little more. I thought CHI would put in the backups too and you would be ok. It's tough to figure out which teams are going to 1) Show up/play hard 2) Keep in their starters...week 17 has always been tricky for me when players start sitting out or teams start getting extra motivation (which I do believe in) and momentum because blood is in the water.
Hope you hit your Colts bet tonight. I'll be rooting for you!