Are my two tom cats going towards friendship, or am I going to have to give up one?

First of all - ALL your cats need to be altered without delay! From what you are saying, they probably will all learn to get along then. However, you may have to put up with a few squabbles while they are jockeying for position in the "pecking order". One will probably end up being the "boss". I got our cats from a shelter and the largest one, 7 year old Spooke (the big Kahuna) very definitely is the "alpha" cat. Make sure they all have plenty of places to sleep and let them go unless they are seriously injuring each other. Spookie gets into a fuss with Miss Peaches every now and then. She is only 3 and defies him by growling at him. Hang in there - they will eventually forget that they ever were not a cat family. BUT GET THEM ALL ALTERED.