Ferrets are a huge responsibility and very expensive, comparable to a medium sized dog. Plus ferrets can live up to 15 years.

Rats are great pets, cheaper in the long run but expensive at the start. Unfortunately, pet store rats actually average 18 months of life. But I've had rats live longer than 3 years from pet stores.
Cages must be quite large, even for rats who spend hours outside of their cage. They should be a minimum of 16 (preferably 18) inches on any side. The reason for this is because a small pet should be able to stretch out completely straight, including their tail, on any side of the cage. If they constantly have to be bent or hunched over, they can develop back problems. I think a good minimum for two rats is 2'x3'x2', and this is hardly much more than a person living in a one-room apartment. I'd nix the exercise wheels as they take up too much room, are argued to be too dangerous, and the typical rat prefers to just use them for another roosting area. Outside of cage time is more important.
My most personable rat would follow me around and try to climb up my pants legs. My least personable rats I couldn't handle at first, but they came around enough to pick up if I had to. They're too individual to say for sure what yours would be like, but most are very friendly if handled well.