Depends what kinda wheelin you're into. It would be a lot cheaper in the long run to build up the suspension on the 80 Toy vice the IFS Toy...
Also consider that although "rough" that 1980 Toy is a classic
I can tell you from experience that after I sold my 88 4Runner b/c of a bent frame I regretted it later on...It was a classic
Why not have both and build one for rocks and one for mud