1) Light bar if they'll still do it.
2) Retractable tonneau cover
3) Accessory switches
I'm wrapping mine too. Contacted a company that does the wraps and they're doing some mock-ups: black with either a flag or eagle (patriotic) somewhere on the vehicle, but subtle. Haven't seen the mock-ups yet.
I've also decided that I want 37" tires. The dealership didn't know about this option, so I'm assuming the tires will have to come from a local tire shop (i.e. Discount Tire). The challenge is finding a 37" tire with lower drag. Most of the mud tires will kill the mileage. The Nitto Recon Grappler resembles an all-terrain tire, but looks decent, probably has better mileage, and comes in 37/13.50/24. I want a large diameter wheel, though I see that some of the people commented on another thread that they don't like the large diameter wheels. "To each their own" -- I like large wheels.
Goodyear did a custom Wrangler All-Territory tire for the Hummer EV. It'd be great if they'd do a custom 37" tire too, so that could be an option, but I doubt that they'd do it for a 22" or 24" wheel.