Rear ride height without air shocks.

I like your 2nd photo better than the 1st. I'm not a fan of air shocks myself. If you want more of the stink bug look, I'd either get some new springs with whatever height you seek, add a helper spring, or put on some coil-over shocks. Keep in mind that some coil-overs have too big a diameter spring that will rub on the fuel tank. You may have to look at a few first to get ones that fit right without rubbing anything.
I had the old clamp on helpers on my first Dart back in about 1970. I bounced over some rough railroad tracks at 60 mph and lost the tank. Damn overload coils grabbed the lip of the tank and peeled it out from under the car.