Lol sounds like my house. I think mine takes 3 bathtubs full, but my kitchen sink runs out of hot water quickly, so I'm going to pick up a large stock pot tonight and boil that on the stove while filling the pool.
As for the pump, I rented the pool directly from the midwife and it came with everything...pool, liner, air pump, sump pump, sink-to-hose connections, all for $55, and if I don't end up using the pool, then I get my money back. MUCH cheaper than renting just the pool from anywhere else. I was looking at $125 as the cheapest, and that was out of town.