I don't think the Colts will be making another big trade for a guy like Watson or Cousins. Have to imagine the front office will be gunshy after how badly this trade blew up in their face. With that in mind, there's only two realistic options; Jimmy G, or Teddy 2 YPA.
Bridgewater: 18 TD/7 INT/3K yards/7.2 YPA
Garoppolo: 20 TD/12 INT/3810 yards/8.6 YPA
Both guys are firmly what you see is what you get. Bridgewater is the most pedestrian of pedestrian QBs with little arm or desire to throw past the first down marker. Jimmy G is much more of a boom or bust type player. He's capable of great play but will then inexplicably start straight up missing his WRs or making horrendous decisions.
With how the Colts are currently constructed to be a run heavy, more basic offense i'd have to assume Jimmy is the better fit. He'll take chances where Teddy will piss himself at the mere thought of throwing beyond 5 yards past the LOS.