As a old school type of rodder, I am not real fond of most of the store bought ready kits. In my opinion ( and that is JUST my opinion
) they are not sturdy enough and rely on one off and specialty pieces.
On the truck I am doing ( a non Chevrolet ... ) I am using a 85 Jaguar XJ6 front suspension. It has 11" disc brakes, a power rack, and the rotors have the standard 5 on 4.5 Chevrolet wheel pattern ( but with 1/2 - 20 Ford thread wheel studs
). The entire cradle bolts out. Cost was $300 at the local boneyard.
Go here ... to see the conversion ...
I believe that this type of suspension would adapt to a 55 to 58 Chevrolet pickup very easily.
Others have successfully grafted Camaro/Nova subframes into those trucks. I have a friend who grafted in a 79 Malibu front suspension.
The advantage to adapting a suspension that was readily available is that the parts are readily available also ...