If your Colorado is the 4 cyl 2.5L, it is rated to tow up to 3,500 pounds. If it is the V6 3.6L, with the towing package, it is rated to tow up to 7,000 pounds.
The 19 and the 22 model C-Dorys have the same space in the V-berth - plenty of couples cruise in the 22. Ruth and Joe (R-Matey) spent a lot of time on their 19, which was later owned by Greg (Aurelia, boat name Ari, family of 3) who also spent time onboard. That particular 19 did have a solid bulkhead that Joe added. Most of the factory 19s are open to the cabin, with a canvas covering.
I am no expert on the 19, but there are folks on here who may add to the conversation who have a lot of experience with that model. My take on it: not that much difference in weight between the 19 and the 22 (figure 4,200 pounds +/- vs 5,000 pounds +/-). I've read that the shorter hull of the 19 does handle different from the 22.
As far as your 5hp kicker - we used a motor smaller than that on a 25 as our dinghy motor and a potential use for the 25 - it will work on the 19 or 22. We had an adjustable bracket for the 2.5hp motor on the 25: it would move it at about 4 mph in still water.
Hope that helps - you'll hear from others with more experience with the 19 and 22.
Jim