Charging at the track

sorry to bring this back up, but i found out that the deep cycle battery idea replacing the car battery and charging off of it is not going to work to efficiently, so my idea is now to buy another car battery (high Cold Cranking Amp capacity) and charge it in my house, but in a small safe storage container, )my parents don't like battery acid in the carpet, it clashes with the drapes.hehehe). back to the matter at hand, what battery is the safest (least likely to leak) and cost effective to get?, and what container would be safe to transport the battery in? Rubbermaid tub?, cardboard box? or something else.

thank you for your input.