???? Deck hinges ????

Well I'm at the point to start adding hinges and I dont want to see them bolted down on top of deck, and all the piano hinges I've found would attach to the sides of decking (plywood) and thats a weak spot in wood and will not last. So i found these on EBAY and really want some because of how they will mount under and be stouter. Not the biggest fan of that site and was wondering if any one had used them and where else I could find them???

Those are the proper hinges for plywood lids. and if you want to get super crafty you put t nuts in the top side and bolt from the bottom side. then carpet etc covers the t nuts.

Just make sure that they are stainless steel!!! Dont want to replace them after a year!!!

Or Ali.