[dsraven]

study up on independent front suspension systems and theory
study up on rear suspension systems and theory
look online at what manufactured frames look like and pic features you want/like
check sites like welder's series for brackets and items you want/need but can't fab in a hurry or don't want to fab
draw up a plan of what you want to end up with
run to the scrap dealer
pick up some straight pieces of scrap I beam
make a frame table
take your drawn up plan and then make your own frame from rectangular tubing the way you want it with the components you want. the frame doesn't need to be the same width as the stock frame, just needs to be the same wheel base and have a track width that will work. the cab mounts can be built or modified for frame width. tack it together and have a welder finish it off for you
when done sell the table or take it back for scrap prices

this would beat the idea of cutting off the front of the frame to sub in a front end from some other vehicle, then cutting off the rear of the frame to fab up a new rear suspension and really only using the center section because it has the cab mounts. those mounts are so easy to build you wouldn't need an old possibly tweaked frame. if you have an old 1 ton frame steal the cab mounts off that and fab up your own new frame using those cab mounts. get the frame dimensions from an assembly manual and start cutting steel. if you look at a diagram of the original frame, in the assembly manual, you will see it would be an easy frame to copy if you just want a copy of the original. if you want a more custom frame the dimensions are there for items like cab mount locations, rad support location, axle center line etc etc.

a nice frame is one from Canadian Hotrods in Tappen BC. corvette underpinnings, fully boxed, hidden brake lines, battery cables etc. set up for whatever driveline you want.

just saying, a new frame may not be out of reach, budget wise, if you build it yourself.