Those being the Panthers and Texans, and inquire on Corral and Mills. I have loved Corral for years. That offense he ran and how well he ran it had multiple reads going on constantly, which shows me he can mentally handle this level. He just needs seasoning and McVay would be perfect for him. Mills is the second choice of the "maybe they undervalue their QB option" sweepstakes as he has done some good things to date. He certainly has value as a backup. So I don't expect either to be easy to get however you never know so I'd give it a good shot.
My draft targets would be O'Connell and Haener. Both look like nice fits for McVay's scheme in that they can make quick reads and keep their eyes downfield. Haener is probably more of a project with his mechanics but none of that concerns me when you see that competitive fire he brings.
As to the FAs the best option for McVay as a backup is probably going to be Minshew. He's got a lot of character and has the skills you need for this offense. I'd like to see them pair up if they can't go get a younger option like Corral.