You're going to have at least $20,000 into it any way you go for what you want. These cars are not inexpensive to build, unless you place them back into factory spec.
Just some general parts estimates;
GEN III 6.4. $6,000.
Hotchkis sway-bars, torsion bars, subframe connectors, and tuned Fox shocks. $1,600-$2,000.
US car tool for all the frame stiffening/bracing parts, like torque boxes. $500-$1,000.
727 transmission with hemi flexplate & spacer kit. $1,500.
Torque converter. $600-$900.
Dana 60 or 8 3/4 with new limited-slip differential. $1,500-$2,000.
Big brake kit on the front. $800-$2,000.
Brake kit for the rear. $600-$1,000.
Vintage air and all related components. $1,500-$2,000.
Modern Wheels / tires. $1,500-$2,000.