He lists his recommendation on which upgrades you should do first on his site. I've done the following upgrades from Jon:
Fuse panel
headlight controller
console controller
ac controller
controller mounting panel
led gauge bulbs
led courtesy light
led footwell lights
internally regulated alternator
flasher upgrade
ignition controller with push button switch
i just did Wilwood brakes on my car so my brake is all set.
he provides very detailed installation instructions and almost anything you do can be reversed back to factory if for some reason you wanted to do that
considering adding the fan controller next winter. I like what he's done with the switches but prefer the original factory look.