You should check out the deluxe rooms at Boardwalk Inn. The rooms are quite large, sleep six in three queen beds and have the benefits of club level services - continental breakfast, snacks, evening canapes and desserts. With six in your party, a club level room may well be worth the extra cost. Other possibilities you might check out are junior suites at Wilderness Lodge (includes Club Level privileges) and junior suites in the garden wing at the Contemporary (don't think this includes Club level privileges).
Personally, renting DVC points doesn't make sense to me because the points required for weekends cost so much. The only way renting points really pays, IMO, is if you're willing to move to a cheaper hotel for Friday and Saturday nights. With a family of six, I can't imagine trying to move elsewhere for the weekends. If you do want to stay in a DVC two-bedroom, watch these boards for discounts -- AP rates, publicly available discount codes, and then book through CRO if you can get a discount.