Hertz g suspension.

My understanding is Xr7g’s came with heavy duty suspension’s. Mine is a hertz g 390 4 barrel, and I will be replacing most if not all of the suspension / steering parts. I plan on using Moog parts for the front and Espo springs in back, unless their is something better. From my research there are different sizes of front sway bars, coil springs and leaf springs. My question is what parts are the heavy duty? Front and rear springs, front sway bar and front and rear shocks? Also do I use the 390 gt platform to price and acquire these parts or do I use something different?
Thanks Scott:

Consider getting extra lift leaf springs to prevent that saggy butt look.