Thanks everyone - I just knew I could trust you all to give me that final bit of encouragement I needed !
We are going to home Buddy on a trial basis and just waiting for a call back from the fosterers. The existing five come first though and I am prepared to give him back if any of them are unhappy once we have given things a fair chance.
MM, the girls are all CP rescues, Gizmo, 9, very laid back persian but definitely the boss, her daughter half-persian Bubbles, 7, sensitive little girl, and three short haired tortie sisters, Daisy, Ellie and Cleo, aged 3.5, quite shy but all five extremely loving and gentle. Will keep you posted.