Okay, thanks for all the opinions and advice. I brought all the boys and 2 of the girls in tonight for a photo shoot, and after studying the pics, I think IF I keep one I'll keep the second one. He's definitely got the nicest shape, and his vulture hocks don't really show. He's been handled most, because he's the one we were originally thinking we'd keep, so he's the most friendly at this point.
I also got pics of two of my girls, and while they're far from perfect, I think they're shaped better than the boys. I like pullets' looks better than roosters' generally anyway. I originally ordered them just to set eggs for me, and not even thinking I would breed them. They will serve their purpose perfectly. They're definitely the sweetest chickens I've owned so far, as they're really calm and sociable.
It's amazing how much more you notice what your birds actual shape, etc., are when you look at pictures instead of the real birds...
These cockerel shots are the 2nd one I posted before. The others are, obviously, two of my pullets.