A Children's Python, Anthill/Pygmy Python might be the way to go. They tend to stay small, are mellow in terms of their temperament and they only grow to around 3 to 3.5 feet when they're full grown. Here's a link with some more info about them.

http://www.reptilechannel.com/reptil...-python-2.aspx

I couldn't find a care sheet for them on the forums on here. You could do a Google search and find several for them. Make sure to look at several to make sure you're getting accurate information from the care sheets. There are a few people on the forums that have them and hopefully they'll chime in with some info if you're interested in them. Good luck!