I haven't read through the thread yet, and I hate to be one of those "OMG my breed is the best" people, but from what you describe, a Greyhound could be right up your alley.
We adopted ours 2 years ago, and she's been awesome. Loves to walk and run, but when she's indoors, she a cat. Always curled up on the couch or the bed, and she loves to spoon. Super friendly, loves car rides (ours does anyway), and generally laid back and chill. Very quiet, and while they do shed a little, its nothing like the shaggy breeds. I'd recommend heading to a greyhound shelter, and at least meeting them. I knew nothing about the breed until we stopped in to visit them, and they were so awesome.
Cheers to you for adopting, though. No matter what breed or mix you end up with, you're giving a dog a home, and that's the most important part.