I'm pretty sure (but not certain) that the answer is no.
SSR will not be open in April. My understanding is that SSR owners cannot use their points to stay anywhere until SSR is open.
If you are buying resale, I do not think you will close in time (and get your name in the DVC system) in time to make a reservation for the first week in APril. Even if you could, you would be reserving less than 60 days ahead of time - availability is usually quite limited that close to arrival. At the 60 day mark, DVC allows CRO to rent any unreserved point rooms to the general public for cash, so the odds are not in your favor.
This would be a good question for your guide. Maybe he/she can work something out for you. Wouldn't hurt to call and ask.
Best wishes & good luck with your decision to buy!