It really depends on your travel dates.
Are you flexible? I've booked VGC at 7 month in low period season. At 7 months I've seen a lot of availability in April and May. If you want to visit during Summer or holidays it's much much more difficult.
However you cannot have all resorts (unless you can buy a LOT of points), and almost all resorts you mentioned can be hard to book in certain periods.
So I would consider to buy SSR points, they are the cheaper points to use for booking other resorts.
Or if there is one resort that you know you really want to visit during peak period, buy that one. Otherwise, to often change resort, buy the cheapest one (SSR).