What is the best way to seal the valve covers. Should i go with the molded rubber or just use ultra grey? With thegrommets, should i go aftermarket or dealer?

I have used a generic kit off eBay, no problems. just make sure the grooves for the gaskets are very clean and lubed to seal. be careful of evenly torquing the covers on, even pressure on the whole gasket, just ask a drummer about tuning a drum, tighten each bolt a little at a time and move around between them. and the vents for the valve covers is where i see the most oil leaks, usually just dirt and a bad seal. Clean it, lube it, clamp it.

I have used a generic kit off eBay, no problems. just make sure the grooves for the gaskets are very clean and lubed to seal. be careful of evenly torquing the covers on, even pressure on the whole gasket, just ask a drummer about tuning a drum, tighten each bolt a little at a time and move around between them. and the vents for the valve covers is where i see the most oil leaks, usually just dirt and a bad seal. Clean it, lube it, clamp it.

what should i lube it with?

I use petroleum jelly, vaseline

Or you can get the grooves and the gasket sparkling clean, and then coat everything with some gasket sealer.  Also put some gasket sealer between the special washers and the bolt stem.

the seals and grommets are made to work with regular motor oil , if you put an adhesive sealant on them then it affects the way things move when heating and cooling, causing binding and leaks.

keep things smooth clean and lubed! things that men find desirable on cars and...