Any suggestions you guys can give about when to start as far as suspension brakes handling etc.
Congrats on the new car!
If it were me, I'd start with the front end. Check/replace the ball joints, tie rod ends, steering gear and idler arm. Unless they have been replaced already, the control arm bushings, upper and lower should be replaced. If your torsion bars are under 1" in diameter, replace them with a set over 1" (IMO).
If original, the steering box is likely a little 'playful'. Freshly rebuilt ones from Firm Feel or Steer n Gear are in the neighborhood of $350-$400 I think.
I would do the above before I fitted the Nitto 555's
The above would be your 1st 'winter project' spending spree of owning an e-body.