My 2 cents..

May be mistaken, but I believe Hobie tramps are all vinyl..one style is just solid while the other is mesh. For Hobie tramps the solid is cheaper, but I believe it is currently only available in white. I've owned both styles of Hobie tramps, and do not believe there is any appreciable difference in how tight they can be laced or how much wind blows through. Don't have any experience with aftermarket tramps, but you can tighten a Hobie mesh tramp plenty tight. I prefer the mesh....sheds water better which also allows sand, etc. to be removed easier......and looks more sporty to me. However, on some windy winter days when the water's flyin' everywhere, the solid is nice!

That said, whatever tramp you get will probably last longer than your boat. No way I'd be buying a brand new tramp for a boat that old. Used ones come up quite often on Ebay and the Hobie and Beachcats classifieds.