I poked around on summit and jegs, cp performance ect, and didn't find any that would work with center riser exhaust.
Use some gojo hand cleaner on those rusty ones, and about 90% of the rust will come off. And at least be presentable. Or get the same chrome ones again, pretty cheap. Doesn't solve the typical leaking problems of stamped steel tho. 3M "gorilla snot" weather stripping adhesive the cork gasket to the valve cover and let cure.
Grease the bottom of the gasket prior to assembly, just a thin coat. This works wonders.
Using open element breathers will help alleviate back pressure and helps with not pushing valve cover gaskets out.
Hope that helps.
Dan'l