if you don't want the tubular upper arms and all that, then just order the disc brake kit from dr diff. the one with the repro a-body spindles and bolt it all on...

my car had the FMJ spindles and some tubular upper arms i didn't want to risk, so i ordered some upper arms from firm feel, swapped the spindles side to side to put the calipers in the front and got some brake hoses from dr diff (though i could've used the factory 74-76 a body brake hoses and saved $30)