Mike: Regarding the fuel pump, you will get all sorts of info about not using an electric pump and/or engine pump and going gravity feed only and keeping the system "simple." The choice is up to the builder. I like have positive pressure to the carb (especially during T/O's and landings.)
I am using the Facet electric fuel pump (the one with the AN fittins built in). Gascolators...not too many to pick from. They all do the same basic thing, just in a different package. I went with the Usher and bolted it right onto the firewall. I also picked it because of the extra port on top where I installed my Van's electric primer. Order an extra set of replacement gaskets and filters/screens for whatever unit you buy. I have the Plane Power alternator (came new with the engine) and it has the voltage regulator inside. Master and starter relays...pretty simple choice from Spruce. Only one of each.
The cover that the vertical stab/fin sits on ? That cover ? If the builder made the cover in one piece I think the only way to gain access to the trim is to remove the rudder, then the fin then the cover. Check yours again. The sides maybe be removable or hinged. That's why most builders build the cover in (3) parts. I included a pic of mine during the building process. The side are removable with the fin and rudder in place.