[Ford Prefect]

I'd stay away from the Welsh Corgi. They're a wonderful dog ... one of my favourites in fact. But a friend of mine has one and they're a pretty high maintenance dog that need a lot of personal time and attention, which from the sounds of your situation may not be available. It almost sounds like you need an older dog. I cringe at the idea of pretty much any breed of pup being left alone all day, five days a week. Not that I think that's bad for the dog, but with a pup it might be really bad for your upholstry, and rug, and walls, and curtains ... you get my drift I'm sure.

Edit: In your situation, Cow Person's suggestion to get a cat is a good one. Unless you're a cat hater that is. Cats are even lower maintenace than fish, and if you treat them right they make good companions.