You need a two bedroom unit unless you stay at the AKV. At the AKV, 5 people are allowed to stay in a 1 bedroom (standard or savanna or concierge categories only). There is a sleep chair in the living room for the 5th person, in addition to the sleep sofa. Only AKV has the sleep chair (but not in the value category).
With 5 adults, I'd recommend the 2 bedroom. You'll appreciate having 2 bathrooms, and only the parents will have to share a bed (or sleep sofa).
There is a link at the top of the forum that will tell you how many points you'll need. It depends on when you want to go as well as the resort you choose.
If anyone wants to discuss occupancy issues further, please do so in this thread.