Just a little info for ya. I looked into making a jelly fish tank but ound out quickly why they don't work and why they aren't sold. They generally need cool water or they melt away. Also they can't survive in an aquarium with corners. They need round tanks with powerheads blowing a current all around the tank or else they just get stuck. That pretty much means a custom setup that I did find on the net but cost somewhere close to $10,000.
They are cool creatures though, just not meant for the standard aquarium.