I'd agree with Martin. The easiest route is to keep what you have and just make it better with an electric p's unit and a brake booster.

Don't fall prey to the myth that trucks of this vintage can't be driven at speed because they don't handle well. They handle just fine at high speed with radial tires and properly functioning steering and suspension.

Adding an electric p/s system and a brake booster is pretty easy compared to cutting the frame and adding a whole front clip with discs and IFS.

As for disc brakes, don't assume they'll shorten your stopping distance. Adding them may even increase your stopping distance. Four wheel drum brakes are used on dump trucks and tractor trailers for a reason. They work.

You're only benefit to adding disc brakes is that they won't overheat as quickly if you're standing on them while coming down a mountain or if you make hard stops in quick succession at high speed a la auto cross racing.

I drive my unrestored and unmodified 1950 3100 on the interstate every week. It tracks straight and true and can handle curves without excessive body lean. Of course with a 216 I don't get over 55 too often but if it was capable of greater speeds I wouldn't hesitate to drive it faster.

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)