Yes your calipers will fit the early hubs/discs.
Seems you have the Topline list covered but maybe new idler and pitman arm bushings also (not knowing the present condition).
Kerscher is the best source, order them direct.
Try Tweeks, Performance Products, or Pelican Parts for the discs and pads (all are online).
With all your planed mods the Design 90 will fit without spacers.