If using RCI, then I would stay at:
Sheraton Vistana Resort
Holiday Inn Orange Lake Country Club (any of the areas there)
HGVC (any of the 3)
Vacation Village at Parkway
Keep your powder dry---Wyndham has not yet deposited March '13. In fact, I don't think they've done February yet either, and they tend to deposit one month at a time. February could be any day now, March will probably be another month.We have a week through RCI to use at the end of March. Looks like WBC is not available.
If for some reason the March deposit, when it comes, does not work for you, just place an ongoing search with a healthy number of the "usual suspects". Orlando has a ton of inventory and cancellations happen all the time.I wouldn't wait too long to grab a March unit, however, or you might limit your options.