well, if your overly worried about the floor caving in. Go with a large footprint, and for the base of your stand, make it completely flat, the whole bottom of the stand touching the floor, not just the edges and the main post. Its a trick that is used on the rigs to move the 120000+ lbs worth of equipment, use as many tires as possible to spread all the weight equally all over the place. So if you go with you original dimensions (60" long, 24"deep) thats 1440 square inches of floor space used and about 1100 lbs of weight thats 1.3lbs per sq inch
. Not a whole lot of wieght to be supported when you use all the floor space you can to hold the wieght.