Gear oil - any standard 90wt outboard lower unit oil will work.
Trim oil - pretty much any power trim fluid will work. Some folks use ATF. Whatever you use, best to drain the old before filling with new as some hydraulic fluids don't play nice with others.
Spark plugs - recommended were Champion L77JC4 or QL77JC4
While looking up plugs for my 76' Stinger an alternate plug is also listed. Champion UL77V surface gap plug that I run in my 50hp. Any advantage to the surface gap plug?