You have to pick one. They don't allow stacking (using more than one discount at a time).
QSDP is 'worth' $30/night per adult and $9/night per child 3-9.
You'll have to figure out if that saves you more, or if you save more with the percent-off on your resort room.
^^^ How many people will be traveling? How long will you be staying? I think in general it's safe to say the 40% off deluxe resort offer is the better deal.