I would suggest getting a female.... My Rocky and Mickey
usually get along (Mickey is neutered, Rocky is not).... but sometimes it just seems like Rocky starts fights with Mickey over nothing (my attention usually).... Rocky is 3 pounds and Mickey is over 8 pounds... there is no way Rocky can win a fight but he always starts them....
I think females are more laid back and don't fight nearly as much as the males do (just my opinion). They usually give my males kisses...
Best of luck with your decision!