Seal packing is a must. Without it you will have large oil leaks. The annoying part is that, for all its cost you only use a few dabs of it. Unecessary things, but worth looking at while you're there is the condition of the plugs/coils.
I don't mean to discourage you but if you were confused between the head gasket & valve cover gasket I would hope you do some research on what goes into removal & reinstallation before you buy anything. It's an exceedingly simple job but even something stupid like not cleaning the mating surfaces, overtorquing the valve cover bolts, etc will make it a headache in the long run. Once you place the packing you only have a few mins of a window to get the cover in place. Be sure to use a torque wrench on reassembly as well
My plan is to paint mine when I do the job, thats why I'm waiting for warmer weather. I can hardly wait to degrease the engine bay and have it stay clean.