do your homework on what company to go with. seems the only reliable people out there are the tcbros, but they look like shit so it doesnt really matter.
you will need to find someone that can weld. not your buddy that just got a welder from his grandpa and wants to try it out on something.
to add to the list already stated
pegs
brake linkage
chain tensioner
and something that i usually say when people ask this on the forums.
whatever you time frame, double it
cant weld? have a buddy that can? almost triple it
can weld? broke? triple it
whatever you think you will spend in time during the ordeal do the same with cash.
ive made 3 or 4 'last orders' from mikesxs. all things that i didnt know i needed, things that came up, things that i thought could wait, etc. etc.
off the bat you will need to replace all wiring components. coil, regulator/rectifier, key switch, battery. you will pry need new seals almost everywhere. new tires, and brakes.
in all honesty unless you have the fabrication tools and skills!(or a giant wallet), a massive fucking order from mikesxs, a bunch of tubing, plate, sheet, rod, heim joints, springs, carb cleaner, (your building a chopper so) air filters, new mains, new pilots, new tank or some sealer, and taps is maybe all youll need to get started on building your bike.
have fun