Hey, welcome to the Board! You have a hard choice. From what I've read, the Stinger is top of the line. I don't think 45 dives should not put much wear and tear on it. Plus, you know its history because you would be buying it from your cousin. On the other hand, the Vyper is a good rig too and is bigger and easier to read underwater. I don't know what price you are going to pay but Leisurepro.com is selling the Vyper and Stinger for $325 and $499 respectively. For my money I would go with a new Vyper as opposed to a used Stinger.