I've heard good things about the La Bassine waterbirth pool, but the price tag can be prohibitive for women on a strict budget. I found a similar inflatable pool for about half the price, the Sevylor Electra Round.
Similarities: Both have upright I-beams and an inflatable floor.
Differences. The Sevyor holds 72 gallons, La Bassine 100 gallons. The Sevyor is round, rather than slightly oval, and doesn't have handles inside.
This might be a good alternative for people wanting something a bit more sturdy than your standard fishy pool. Sometimes the horizontal rings give way under pressure, creating a lovely flood in the living room. Not fun.