I'd pick Rusty. He's not too far removed from being a competative driver.
Seems like a joke to have Sterling Marlin and Terry Labonte in it when they're both actively trying to make races still. May as well have gotten Jeff Gordon and Kurt Busch.
Spencer may cause the most wrecks but I doubt he'll win. Rusty will probably win (he said on Wind Tunnel that he has his Nationwide team "putting the finishing touches on the car") but hopefully it's Cale, Johnson or Gant. Harry Gant was in his prime, winning Cup races at 55 (I remember his win streak win I was like 8).