I do not think your 5 person will pull a 1 BR in RCI, despite some sleeping 5. It it likely only going to pull 2BR. 57 TPUs is plenty for a 2BR in summer. So, if you want a 1BR, change your RCI search to 1Br for 4, and then just call member services @ DVC after your get your reservation to add all the names, including 5th person (that is what I have done 3X). Leave out SSR. I think you will have 99% chance of getting either AKV/BLT with such open dates, with AKV being much more certain. You might consider OKW, which has sleeper chair. Great pool area, great Key West theming, fun community hall/boardwalk area with shuffleboard, games, bike rentals, snack bar. My teens like it a lot. It is our 2nd choice after AKV.
VWL all have sleeping chairs now, but my kids find it sort of boring, but easy boat ride to Ft W with lots to do.
BVW and BCV do not have sleeping for 5th person--it would be bring your own sleeping bag/air mattress. DVC might or might not let you register a 5th person in those units.
You will mostly likely get a hit for late June dates (as those will be loaded 1st),probably around December. There is tons of availability by 8/20. I had my pick of 1BR units last year between VWL, OKW, SSR, AKV for mid Aug. arrival. Aug. hit around early Feb. in RCI.