A drag king, or, a woman who dresses as a man in the name of performance, is somewhat of a rare bird in the same locales in which you'd be unable to throw a stone and not hit at least 30 drag queens.
Drag kings are (seemingly) much more into performing than just showing off. However, be aware, there is quite an actual difference between the two. Performing generally requires talent, whereas showing off is best left to runway models and so forth.
A typical drag king show usually includes a multitude of acts by drag kings, all of whom are dressed to the nines in men's clothing and have erased every vestige of femininity from their appearance. Many prefer to wear suits or tuxedos, but practically anything goes at most shows. Facial hair is drawn on the face with an eyeliner pencil and looks shockingly realistic. If the performer isn't going for a 1970s look (which is quite common), then he usually has short hair to begin with. If he's going for a Sly (of Sly & The Family Stone fame) look, then he may use an afro wig or style his hair in such a fashion, if possible. Breasts are bound with Ace bandages, back braces, or actual chest bracers that are designed to flatten the breasts of the wearer. The front of the king's pants are almost always stuffed with a pair of socks, or with what is known as a "packin' dick," which is a specialized type of dildo designed to feel like a real penis, and to add the necessary bulge to the crotch area. (Think David Bowie's "area" as the Goblin King in Labyrinth and you'll get the general idea of what it's supposed to look like.)
I know quite a few drag kings, and all of them are homosexual women, much like a large percentage of drag queens are homosexual men; blurring the boundaries of gender perception is more or less an active definition of each community.
And then there's the shows... oh, the shows! Unlike most drag queen shows I've witnessed, drag king shows are packed with energy, excitement and coordination (as in, actual rehearsals prior to the event). The music is generally a lot livelier, the performers are much more into what they're doing, and there's a lot more cooperation between seperate performers. Maybe I just haven't been to any high-class queen shows, but the king shows I've seen have always exhibited a lot more audience energy than queen shows. But then again, most of my experiences with drag have occured in New Orleans, where the only thing good is the coffee. (And the drag king shows!)