That would rule out the B1G. OU's academics are borderline good enough for them (lack of AAU notwithstanding), and OSU is much lower ranked than we are.
The ACC is already sitting at 14/15, so unless you guys plan on moving to 20 (something I just don't see), there's only one spot available (with the other one on permanent reserve for the Irish).
That leaves the PAC and the SEC. Those west coast boys already turned down a package deal of OU/OSU once before. But given how the landscape has changed since then (their network being a disaster so far, and the ACC officially getting an ESPN-backed network), I'm not sure they'd turn us away again.
As to the SEC, I'm not sure what to think. On the one hand, OU football and the SEC just seems right. On the other, I have no idea if they'd be willing to take the pokes just to get us.
There are a lot of variables that could play out in any number of ways. The next decade or so should be very interesting.