BWV is a good choice if one plans to use the standard view. I don't see enough info to make a good recommendation in case your current options falls through. What villa size, time of year and how many points are you looking at?
A 150pt contract will get you between 7 and 10 days during July/August in a studio (depending on view), so this assumes you are only interested in studios.
I'd buy the least you'd be happy with. I wouldn't buy OKW to get more points, I'd buy SSR if that was the goal and I was OK staying there part of the time then try other resorts most of the time. Long term SSR will be cheaper than OKW and will avoid the 2042 transition issue that adds significant risk IMO. If I specifically wanted BWV most of the time though, I would not buy SSR and try to get in there, esp if you're OK with standard view at BWV. The difference in costs for SSR staying at garden view compared to a BWV purchase for standard view isn't that much over the long haul. OTOH, buying BWV and then using the points mostly at the 7 month window will be a lot more expensive long term. For summer, I think you're safe owning SSR (or OKW) and will likely be able to get something at every resort over time including studios & 1 BR. Studios will be more difficult in general unless the demand shifts by a reallocation. Since you have kids, I'm assuming at least 2. I do think you should plan for a 1 BR at some point for 2 (if 3 or more, a 2 BR) so you might do one purchase now in the 150-200 pt range then a 25 point add on retail. It's possible that a combination of points for say BWV & SSR (or similar) is a good long term goal so you could do part now and then decide later if the goal is still a good one. I'd only do that for a full sized contract up front around 150 though.
Few new buyers actually know where they want to stay most trips long term but many think they know. I can't tell from the OP if they have enough experience to make an informed decision or just an emotional one. It's literally a $10K decision in this situation, usually significantly more when you consider the dues long term. I'd agree that it is not worth the compromise if one can afford it (to me that's pay cash) and truly has the experience to know where they want to stay long term, but most simply don't have that information at the time of purchase. IMO far better to buy lower like SSR and have to adjust later than the reverse. Or better still if one needs a volume of points, say more than 300, buy in the 150-200 pt range then give it a try and adjust accordingly. SSR will be the best value for WDW, BLT will likely be next so if one isn't happy with SSR and is leaning toward a MK resort esp, BLT is often the best choice for that situation. AKV will be next from an overall value standpoint.
We all have moments where we would have been better off making different decisions, both directions. A large portion of my point is that this is a big decision with zero's on the end. IMO it's far better for one to never buy where DVC made perfect sense than to buy when they shouldn't or to make a poor choice on their purchase, and almost no one fairly new to DVC have the sufficient knowledge/experience to make an informed decision. Fortunately, at least currently, if one buys resale and has made a choice that ends up being a less than perfect one, they can adjust for a loss of around 10%. Part of the issue, and part of the reason I think most everyone fairly new to DVC and Disney on property should underbuy if they're not sure based on knowledge/experience (not emotions), is that Disney is such an emotional purchase situation. The chances one is going to spend $45K at say VGF and be willing to sell and rebuy, are extremely low, even if that would be the best choice. So they'll likely keep VGF and try to use it the way they want. Once they're in that situation it may indeed be best to hold on and go forward but the loss over buying say SSR in that situation on say 300 points is approaching $20K and the cost to adjust maybe $4K. There is a big advantage to those looking at a larger points purchase of say over 300 points where they can buy a full sized but smaller contract in the 150 range and give it a try for a couple of years then adjust by simply buying the rest at something that might work better or give them their best options. For those looking to do so resale then add 25 points, as most should buying currently, it might be better to wait on the retail add on until they're worked out their preferences because they can then target their add on to further bolster their best usage.
The chance of getting shut out completely if one is reasonably flexible (most with DVC aren't even when they say they are) and plan ahead at least 7 months out is very low. IMO one can try ALL options over time except the most in demand ones of AKV value/concierge, VGF standard, BWV standard/3BR if they're fairly flexible. OTOH, if one is set on staying at VGF 80-100% of the time in a standard view villa, they'll have to own there but they also need to know that even owning there isn't a guarantee unless they buy a fixed week that fits their plans.
