For a "nicer ride" you could have new leaf springs made to suit your needs. A good spring shop like Eaton Detroit Spring may be able to help you out there.
It'll still be a big truck and won't exactly ride like a car.

For disc brakes check out this Tech Tip: http://www.stovebolt.com/techtips/bigbolts/p30swap/
The same approach could work for your truck.

What do you plan to do with the truck, how will you use it?

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-