I think you'll find some of the accessories become a more personal choice. Here's what I think you "need to have" followed by "nice to have":

Need to have:
-Cabin Heat Assembly
-Avionics Shelf
-Pitot Static System 12
-Pitot Tube 12v
-Boost Pump Assembly (Continental IO-550)
-Fuel Selector Valve (Continental IO-550)
-Rudder Trim Servo (aileron & elevator trim included in kit)
-Gascolator Kit With Bypass Filter (Includes shroud & mounting hardware)
-External Light (Includes wingtip position/strobe lights, power supply and wiring)
-Epoxy Pump

Nice to have:
-Upgrade:Lockable Fuel Caps (get the IV-P ones. They look the best)
-Interior Baggage Floorboard Option
-Upgrade to Carbon Cowls (Fiberglass cowls included in kit)
-Taxi/Landing Light Kit
-Rotisserie for the Legacy
-Smart Tool Level Module
-Die Grinder Mini Air 1/8"
-Diamond Mini-cutting Discs w/ 1/8ls shank (5 piece)

Ron Jones' speed mod kit. (It really makes the plane RG or FG)
http://www.legacy-innovations.com/parts.html

There's other things you can get for the engine/Firewall, but this will keep you busy for the first year of your build.

Hope this helps,
Don Barnes

(Hey at least you made the right airplane choice amongst all the other manufacturers!)