If hes the kind who wants a pal then id get a boy of 1-2 yr, friendly lads like to wrestle, girls tend not to appreciate that kind of play!
Males wont spray in the house if a male moves in, however they may spray if you get the wrong newbie, females can also spray. This is why i prefer adult cats, what you see is what you get, kittens may grow up the opposite of how they are when young. Out of my 3 siblings 2 changed and 1 didnt so you never know til they grow up