Maybe a Toller would be good for you? A female is usually no more than 37lbs. They're energetic and active, but aren't as intense as a Border Collie usually. I find them sort of similar to Aussies in temperament, just without the herding qualities, obviously. Most of the ones I know are nice and quiet, and great dogs in the house, as long as they recieve sufficient exercise. Dance doesn't run around all over the place like a maniac (actually, except for Morgan, none of my dogs ever have run around in the house very much). She plays with her toys on her own (or with me) without knocking into things and is very good at occupying herself. They do have a long coat, but I find it to be really low maintenance. I've never dealt with any mats with either Tango or Dance and I don't brush often. Usually once a week. And you might have a hard time finding one that's not a puppy, but they are out there. Anyway, just thought I'd throw that idea out there. I'm sure there's probably a few more that would suit you, but I can't think of anything at the moment.