I would spend your money buying a good deck that stays on your boat.
In the UK PeakUK, Playboater and Palm are good brands and in the USA Snap Dragon. Don't get one with a strap across the middle.
Make sure it's the right size for the cockpit rim, make sure that you have airbags in your boat and then test it by hitting it as hard as you can in the middle when your sittiing in your boat. If it stays on when it's dry it will stay on when it's wet and more strechy.
If your deck has blown once it will blow again change either your boat or your deck or both (and get some airbags).
Hope this helps,
Neil Newton Taylor
www.swiftwaterrescue.at