Go for the cuttlefish (sorry, I'm a little biased). As long as you can spare the expense and time, it is worth trying cuttlefish. In either case (octopus or cuttlefish), the wait to get one can be frustrating. There are a lot of unhappy endings with octopus too, cephalopods are fragile animals and sometimes don't survive the journey from wild to LFS to you. If you are interested in keeping a small group (like three...), cuttlefish are interesting to watch interact with each other. They are not as interactive with humans, but they do notice you (especially if you are their "food slave"). You wouldn't have to escape-proof your tank, you would just have to protect any intakes with foam.