Though both GVs are very nice, personal preference is the Jambo GVs because of the single story arrangement giving large living area and huge porches.
As to availability, based on my tracking of 7 month window on-line, GVs are usually available at 7 months out. That is true of every resort that has them except BWV where they are usually gone. For example, right now, you can get a GV anywhere except BWV for Presidents' Week.