I'd wait 1 or 2 more years, then go after Kevin Sumlin (Texas A&M).
Keep Case Keenum aboard, let them reunite and go to school on NFL defenses. Everything is moving toward PASSING GAME. The new rules, and the ones that will surely come down in the future, are made for it.
Less hard tackling, less hits on QBs and WRs (to reduce concussions and legal liabilities in the future) means the passing game will be the key to the future.
We wouldn't be able to get Manziel, but then again I am not so sure he can translate to the pro game. He's a concussion waiting to happen, IMO. At least with Keenum, he'd have a HC who supports his style of play...and he'd be a HELL of a lot more mobile than Schaub The Blob.
This also dove tails nicely with Bob's need to keep Houston roots alive and well once he chops down the Kubiak tree.
I wouldn't rule out another potential move: Firing Kubiak, making Wade SON OF BUM Phillips head coach (Vance Jospeh becomes d-coord), and then Wade hiring Kevin Sumlin as O-Coordinator. And Case becomes the defacto QB, as well. It'd be a University of Houston SWEEP. Wade keeps saying he wants to be a HC again, and if things keep going badly for Gary's offense...well, you heard it here first, folks.