Well I have 2, 1 male, a year and a half and just got a new female she is 7 months.. Well I got a male first cause usually males are are a bit easier to train, in my opinion.. but... he got so attached to my husband that he is his shadow now...So I decided to get a female, I was jealous ha ha...
. She came in the house at 2 months of age.. My male was overjoyed.. they got along beautifully.. Now about the marking well... I think that all depends if your male has competition.. meaning another male in the house... Well my husband already had another male dog in the house before we got married .. this was a problem... My male Yorkie started marking the whole house and he NEVER pees in the house ... She also was marking around the house.. and it has been hell house breaking her with the current situation...As far as character .. I love both my Yorkies equally.. but my female is so attached to me.. we are inseparable.. But SHE rules the house as far as who is the boss...
I would get a female.. they seem more fragile and need mommy more...
Plus you get to dress them up in nice pretty dresses and bows