I cannot recommend Inna's Cottage enough. The apartment is immaculate and everything you could possibly need is at your fingertips. Inna's Cottage is located in a lovely neighborhood which gives you lots of options for walks. (Note: Hills are steep but worth it for the views!) The location is quiet and private. Every morning I woke up to the lovely sounds of tropical birds in the garden.
Inna is a sweet and accomodating host. She is there for whatever you might need, but gives you the privaacy you want. Knee issues spoiled my plans, but Inna was going to take me out paddling in an outrigger. I am sure it is a wonderful experience.
I don't believe you could find a nice place to stay in Kailua!