Jim, if they can be bent, they can be straightened. The problem might be that you have to over center them for a while to compensate for the current shape. Clamping them down for now will help. If you attach them to a sturdy frame then they should flatten out and stay that way. One other alternative is to cut kerfs into the bottom side of the panels to relieve the tension.
As far as the miter track I would forget it. A sled is faster and easier than setting up a miter track. A sled sits against the fence and the fence can point in any direction on the table and it just won't make a difference. I've considered putting in a t track in place of the miter track but I'm pretty sure I don't really need that either. I have gone both ways with attaching a fence to the table, clamps and t track, and I will say that I like the t track a little better but that may just be me. Bob and Rick Rosendahl just clamped their fences down on the Router Workshop show and they managed just fine. Your sources are different than mine so I would check Grizzley, MCLS, Rockler,, and Harbor Freight first.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.