When looking at how many points to get, make sure you are not looking at the "value" rooms to determine how many points to get. Those rooms go REALLY fast at the 11 month mark (because lots of people want the cheapest rooms! ), so the likelihood of you getting one of those rooms is slim.
We have two contracts: one with an April UY and one with an August UY. We also travel in early may and early december (with some other trips during other times of the year). I like being able to book our stays for early in the UY. So we use our April points for our May trips and our August points for our December trips. That way, if things change and we have to cancel/move the trip, we don't have to deal with missing our banking deadline for those points. As long as we can cancel the trip within 31 days of the trip start date, we still have full, unrestricted use of those points.
We own at BLT and BWV. I like having these two as we like to do split stays for most of our trips. We do MK while we are at BLT and then HS/EP while we are at BWV. We usually do AK on move day since we have to take a bus there regardless of where we are staying. One of my goals on our WDW trips is to avoid using Disney buses as much as possible, so this approach works well for us. It might not work as well for you with the two kiddos, but it's something to keep in mind for future reference. Disney will move your luggage to your new resort for you, so it makes the transition pretty decent.
Good luck with your buying process!