Some other thoughts for your situation. I agree with others - you're eventually going to want a 2 BR if you do
DVC. Heck, I've only got 2 kids, and I think I'll eventually want a 2 BR for our family of 4. But, you can probably make some of the larger 1 BRs work for the time being if you want - good news about those is that you don't really need to own at any of those resorts to get the 1 BRs (well, maybe the Poly Island Tower for the time being, but that probably won't last).
So, short of spending money on direct points at Poly or RIV (which, depending on your budget and preferences, could be very good options) you could either (a) buy some cheaper points like SSR to use for the next few years and decide which resort you might like to target to have enough points for a 2 BR, or (b) decide which resort you want to target for future 2 BR stays, buy enough for a 1 BR now, and then look to add-on later - I think the 2 best non-2042 resorts for that are BLT or CCV. CCV 1 BRs won't work for your family, but those points could easily be used to book 1 BRs elsewhere. AKL is a great resort, but the dues are higher, and I don't think you need home resort priority there, even for 2 BRs. Additionally, depending on your budget and/or desired frequency of Disney trips, you can always think about a bank or borrow strategy at any particular resort in order to make every other year or every third year work.
Whatever you decide - good luck!