I can vouch for Tulsa just as much as anyone on this thread (BA '98 and TU grad). I also live in the Atlanta area now, but will claim Tulsa forever. The hills are there if you know where to find them as Memorial HS pointed out the ones in south Tulsa. Golf ball hill is a beast and great for hill repeats. However, if you wanted to run never changing elevation, not a problem. That said, Atlanta is hand's down hillier than Tulsa. Other good spots to run not yet mentioned are the trails around Mohawk Park and Holland Hall HS and the paths along Highway 169.
The winters can get cold at times, but nobody has pointed out the many freak days of 65-70 in the dead of winter. Summer training is manageable if you are out the door by 7.
The University of Tulsa has a great reputation for academics. It is hard to beat the convenience of being able to walk to campus. If you leave on or around campus you can get to the river for running and Brookside, Cherry St, or downtown for nightlife in less than 10 minutes. Running from campus to the river is ~4miles. If you are still decently fit and a personable guy, I am sure Coach Gulley wouldn't mind you running with the team from time to time.