My male Maltese has an extensive wardrobe made up of stuff from
barkindogclothes.com,
ImAPreciousPup.com, and
Petco.com. I've also found the occasional thing from
Petedge.com and ebay.
Glamourdog.com also has some cute things. There is a LOT more out there now for boys than when I first got my boy.. just keep looking you'll find some cute things out there.