Male dogs can mark, but so can females. Both my females will mark (only outside). Nikka even does a handstand pee so she can get higher than any male. With proper housebreaking and neutering their's no reason to say they'll mark in the house just because their male.

To be honest I have 2 males and 2 females currently and had a male terrier for 16 years before he passed. My 2 females are the ones who can have some issues with eachother. My males have always had a laid back who cares attitude. If I had a choice again I'd get either 2 males or a male/female combo. I don't think I'd go for 2 females again.