Hey guy, frame opinion...
I'm no expert.....
I think it's doable but would be a lot of work! For $75 I purchased a whole front frame section from a yard. Not too many hours later it's resting under the car, welded in like nothing ever happened! It's like it was always there, part of the car. You'd be better spending your time doing that, than making a frame from scratch...just my opinion.
See the frame transplant here ->
http://www.forabodiesonly.com/mopar/showthread.php?t=15895