I have a set of Mr Gasket Ultras on the way (thanks Jegs!).

I am going to glue them to the cover, but not the head. Hopefully they are thick enough to seal without having to crank down on the valve cover too much and risk cracking it.

If I can't get them to seal I'll probably go back to a set of stamped steel covers that will better contour to the imperfections on the head mating surface.