a cat would adjust better to being left alone while at work than a dog would. i got a cat for the same reasons that you listed.
i lived alone, lived in a small apartment, wanted a pet, and worked 8-10 hours a day.
i went to the shelter and fell in love with a cat there and now i have 4 total all from the same shelter.
i've also gotten married and moved into a big house so they have plenty of room to run and play.