There are definitely cats that need companionship and lots of socializing, but there are also cats that are perfectly content with an hour or two of your time, and cuddling in and lying on your bed with you while you sleep can also fulfill that need. 40 hours a week still means plenty of time with you physically in the house. I've had cats all my life and seen lots of personalities. I think it'll be important to find the right cat but they are absolutely out there. I say go for it.