Hey there, We can definitely help with general recommendations for placement and fixture type. Are you looking to illuminate the home and the garden area?
Just to illuminate the cabana. I put up a 38 degree 5 watt light at each corner, but it is too dark in middle. Not sure if I should try to a put a light between each window.
The window placement definitely makes trying to keep the light symmetrically balanced a bit tricky. Using the same up lighting approach, IMO I'd likely say your best bet would be to consider a single spotlight between the (2) middle windows with the narrowest beam spread possible for the fixture you chose.
i would go with a lower lumen output lamp like a 3watt. Its a short building and you want subtle light. Either two at each eand like you said or 5 (2 at the ends and 3 between the windows) but use low wattage.