New friend for Eddie

I just found this forum and I am hoping experienced cockatiel people can help. I had two wonderful cockatiels until this morning. My little girl died in my arms and left behind her buddy Eddie. She was 7 years old and he is 6. They had been together for 4 years and now we are worried that he will be lonely. He used to live with a friend and was very lonely until he met Skuttle. She died of a respitory illness and he is showing no signs of the same. We would like to get a new companion for him soon and would like advice. He and Skuttle used to be in separate cages, but became insepartable so they shared. I have no problems with them living together or separate, but I would like him to have a new friend. Is it better to get a male or female for him, or does it matter. Should I wait a long time or get one soon? Should I get him a new friend at all? I don't know if he will accept a new friend. Thanks in advance for any help.