have some questions about 350 performance parts

[ya it is a classic]

hey guys so im selling a pickup and if i do im guna dump the 1500 that i make off of it into my 72 gmc 1/2 ton 2wd longbox 350 that has 14 thousand miles since a complete overhaul. thats just the engine that had the overhaul. anyways im looking for a 350hp range. im thinking headers, cam, heads, carb. it had a quadrajet on it now. ill try to get parts used so i can to cut down on costs. i would like to not do any internal work since it was just rebuilt but i dont want anything to break also. so if everyone could give some advice on what parts to get that would be awsome! like if i should get long or shorty headers. vortec heads? what cam? different carb or keep the one i have? im not going to take it to the drags(well mabey street racing....shhhhh! ) its my DD 40 miles everyday so i would like to keep it around the 15 mpg range. running on whatever octane 87, 91, 93. (i think those are the numbers) also i rev it pretty high so build it for mid-top end power. also i would like to put a POSI with higher gears in it. i dont know what gears it has but it has a 4 speed stick and the fastest ive gone was 85mph and it was reving really high. (dont have a tach yet). any thoughts on gear ratios? i would like it to do atleast 100. thanks for your time and any input is greatly appreciated.
-chad