There is a shop in Phoenix, AZ called "Desert Rat" which is currently advertising 6" lifts, INSTALLED for full-size chevy trucks at only $1,299.
Even if you found schematics and fabricated your own lift, would you really bet your life on it? :)
I agree with Luke about a solid front axle swap being cheaper to fabricate, but then you're swapping parts like leaf springs, solid-axle differentials, and drive shafts, and having to cut things to make the new stuff fit. You'd almost be better off looking for an older SFA vehicle to build up if you want a serious 4x4.
Still, I HATE my no-travel IFS, so the idea of a SFA swap is still strangely appealing. Maybe some day...
-Derek