First, measure to the finished wall from the flange bolts. How far is it exactly? I think all of the Totos that use the unifit adapter will project further into the room than your current toilet. If the rough-in is exact, they typically have 3/4" space behind them and are in the 28-29" depth range, depending on the exact model.
If you go to the www.totousa.com you can check out the various models and review their specification sheets.