well the setup is the same whether it's a plastic container or a glass/acrylic aquarium. You still need the lights/filter/heater and basking dock. Personally I'd go for a larger container than a 10-20 gal. You'd be surprised how little they really are. Just check the label in the store and makes sure you're getting gallon and not quart size. You can put the rocks/plants or anything else you'd put in a regular tank into the plastic one. Just be careful to watch for bowing. You'd also fill it the same way you would an aquarium. Fill it up to about 5-6" from the top, so they can't escape.
As for not as much fun.. what do you mean? Do you mean the fact that you can't see into it.. because if so, I totally agree. Although they do make some clear plastic containers. I know many here have no problem with looking down on their turtles, and I guess its more natural that way, but I enjoy having them a bit more at eye level so I can watch all their antics.
