Im putting it back together this weekend. Should the cyclinder base gasket be installed dry or goop added?

2 coats of coppercoat spray.......

I always put the base gasket in dry and have had no problem yet. It slightly alters the thickness to use sealer but if I were going to use a sealer it would be the one suggested above.

Very bike specific question IMO, different gasket materials and design have different need. Metal vs copper vs paper vs layered etc. Some models also have history of leaking and may need extra help. Some high compression and or big bores go beyond the design of the base bolts and can "lift", might need something more, and so on.