Suggestions for valve cover gasket (318) rubber / silicone ?

their thermostat gasket and these are the last ones you will ever need !!

https://www.ebay.com/itm/271930814012?hash=item3f5056ee3c:g:pS0AAOSwDh1e6nbG
https://www.ebay.com/itm/272035946054?hash=item3f569b1e46:g:rjgAAOSwPe1T95w~