I have had single cats and now have multiple cats (4). My loners have done very well by themselves, but the 4 we have now are all related so there are times that they fight like any other family, but I do think that they enjoy being with others. I don't think male or female really matters as long as like everyone else has suggested they are similar in personality and age they should do well together. Best of luck choosing and let us know how you make out.