i allready have a staff who is about four years young and a mongrel who is 14 unfortunatly shorrtly to die due to cancer. my problem is shall i get another staff mine is a bitch but not great with other dogs but if left alone she cryes and sulks any ideas?

Personally, at this time the last thing I would be thinking about is a new puppy. I would be trying to keep my older dog as happy as possible, making sure he/she is having good quality of what life is left. It would be grossly unfair on the older dog to introduce a new puppy now. After the inevitable happens, surely you will want some time to grieve?