Is that the parts list I'd need to tune the shocks myself?
only if they tune by pressure, and/or if you want to play with pressures.
basic nitrogen kit info found on crawlipedia from Filthy.
if you need a gauge for pressure you can make up a small manifold with T's and couplers or buy a manifold block to allow for your feed line, a bleeder port and your gauge. get a small valve to feed the manifold.
i picked up a single fill from ORI (it had the manifold and gauge), then snaked it into this, but this is probably more than what you require but same principal tank, regulator, line, valve, manifold, gauge, fill lines and connectors.
Schmidty Racing, has some pretty pieces.
https://www.schmidtyracing.com/nitrogen-tools-s/1847.htm
i bought the piece in the bottom right corner to have a spare gauge handy and get the second no loss fitting i needed.
i never really did figure out why they have an air chuck on this list, never needed 1.