Any suggestions on slant six exhaust/intake gasket ?

I have a 225 slant 6 and I'm getting sick and tired of using the cheap Advanced Auto manifold gaskets that wind up leaking a few months down the road.

I heard that Remflex makes a good gasket that seals quite nicely, but has anyone had experience with them ? What are some good gaskets that y'all have used on your /6 engines?

by the way when installing this new gasket, what is the best way to installing? What I mean is, should I install it without any RTV sealant, place sealant only on one side, or perhaps place sealant on both sides ? Thank you for any helpful information.