[rbohm]

it sounds like you want a restomod so these are my recomendations;
1: a 300 to 350hp 289/302 is about as far as you wantt o go for the street. if you really want more build a 351w. either way you are looking at about $2500 min. if you get a crate motor you are looking at about $3000 min depending on where and what you buy.
2: for a good C4 figure about $1200-1500, but if you want a street car i would suggest a lentech built aod. it can handle 500hp easy and you get overdrive as well. if fact lentech goes a step further and changes the valve body shift pattern from 1-3-od to 1-2-3/od and you can get an electric od lock out.
3: for 4 wheel disk brakes you can spend at least $1000 and more like $2000. however you can get good front disk for about $800, and, using the right axle housing ends, you can get late model ford F150 drum brakes for the rear for about $350-450 for currie ent. and have a better braking system than the early shelby's.
4: suspension upgrades will run from $500-1500 depending on how far you want to go. a good progressive rate front coil spring, 1' front bar, 3/4" rear bar, 4 1/2 or 5 leaf rear springs should run about $400. then you add rebuilt upper and lower control arms and you are now in the $700 range. if you upgrade to urethane or midolyne bushings you get in to the $1000 range.
5: for paint and body work i cant argue with $3500 depending on how much you can do yourslef.
6: interior figure $600-1000.
7: a/c you can get a daily driver system for about $1000, add about $350 for installation and charging.