Have you checked out How to Choose a Dog Breed or How to Adopt a Dog? I've worked with all sorts of breeds, but I've found myself most happy with Humane Society mutts. In fact, I went through several puppies before my two current dogs because people kept begging to take mine off my hands. They were such good homes for them, I decided to let them go and adopt again. If you don't believe me, here's my proof (The dogs are a year old, the kitten is 4 weeks old):

Golden Labs are very personable. They range in the 50lb zone and are very fun. Plus they aren't as spastic as other breeds.

You didn't mention whether you are an active sort or not or where you reside but consider the following breeds:

Aussie - Australian Shepard. These are AMAZINGLY intelligent dogs. Moderate sized. High energy that will need to have daily exercise and a "job" but also very loyal, loving and yet independent.

Russian Sheepdog - Orchowka. A big dog...males weigh in at about 100 lbs plus but very steady temperament. Also a smart and independent dog but not as smart as the Aussie (my Aussie was smarter than most people I know). A bit more rare, this dog will get looks everywhere you go and is intensely loyal. Mine rarely leaves my side (also work from home) and is content with a good romp in the yard or walk. Very loyal but not clingy. Still retains an strong level of independence but is also laid back around others.

Foxhound. This is probably a dog few people think about when it comes to dogs but is a terrific breed that most people overlook. Super low maintenance, great personality, very friendly dog. Unlike most, mine is totally an indoor dog and behaves wonderfully if properly trained when young. I've heard where others think they are hard to train but that wasn't my experience - in fact, I'd say was super easy to train. Nice moderate sized dog that will love to go for bike rides, long jogs or just about anywhere with you. Great with kids and loves other dogs. Short hair is easy to care for and tends to be a very healthy breed with few problems. Another big attention getter when he goes anywhere...people love the floppy ears and big eyes and cant seem to resist stopping to talk or ask about my "big beagle".

If you are a first time dog owner I would highly suggest a French Bulldog. They are a good companion dog and they are usually very calm (around humans).

Border Collies are smart dogs (and some would say the smartest) that are energetic that would love outdoors. I have a Border Collie mix and he is great indoors too, he is still a puppy but he will sleep on the couch or at my feet without bothering anyone. I have not allowed him to get in bed but he sure as hell tries! He loves people and when he goes to the dog park he is more interested in the people coming in, more than the other dogs there.

Collie they fit perfectly to all that you listed as far as qualites

Lab or Lab mix speaking from experience. They thrive in large backyards and love to get out and play, but also love to curl up on couches and such. The pound would be a great place to look, and I'd start with one thats 3 or so years old, so you're past all the puppy potty training craziness. Also look into crate training when you leave if the pups gonna be inside.