1961 C10 Coil Conversion - Narrow rear end?

[ravidmnas1]

Iv got a 1961 C10 Apache Short Bed and wanting to switch the front end over to something newer with disk breaks and also support a heavy big block motor. It currently has torsion bars up front and truck bars in the rear. Would love to have coils upfront like the 64's and up i think??... Its getting a 502 big block so need a front end that will hold the weight. Is there a good swap to do, or a good compleat kit i could buy? In the rear i want to put pretty wide tires, and need to narrow the axle a lot, what are you guys doing to get it narrow. Cant decide if its more cost and time effective to 4 link it and narrow the frame, or do something with the truck bars? Any info would be greatly appreciated thanks!