I wouldn't bother with the Booty Bumper Kit. The price is near the cost of a good quality silicone dildo that you wouldn't need to worry about, and the "kit" portion is practically useless - they're all 1-1/2" in diameter, so the only variance is the length. Measure out 3-1/2" on your silicone dildo, put your hand there, and you have the short. Move your hand to 5" and you have your medium, and so on.
The Tantus Silk Medium, the Acute, or any other of the many silicone dildos out there would be a better choice for not much more money, and instead of lasting one to two years it would last for life.