You will need the upper control arms, the kelsey hayes disks used the small upper ball joint. The prop valve should be the same, I wouldn't worry about that because you're already disk/drum.
You can get some sleeves for the small ball joints to use them with the later spindles, Dr. Diff sells them for $50 HERE. Otherwise you'll need the big ball joint uppers.
Don't know about a kit, but you can pull everything you need except the upper control arms off of any F/M or J body, so you should be able to get what you need at the local wrecking yard.
And I would think you can sell your Kelsey Hayes set up for a pretty penny!
EDIT:
Here's a list of all the Mopars that use the same 10.98" rotor. You can also pull spindles and calipers off of any of these cars. Some will have pin type calipers, but if you grab everything from the spindle out you'll get the right caliper brackets. Some of them also had the 11.75" rotors from '76 to '81.
CHRYSLER CORDOBA (1975 - 1983)
CHRYSLER FIFTH AVENUE (1983 - 1989)
CHRYSLER IMPERIAL (1981 - 1983)
CHRYSLER LEBARON (1977 - 1981)
CHRYSLER NEW YORKER 1982
CHRYSLER TOWN & COUNTRY (1978 - 1981)
DODGE ASPEN (1976 - 1980)
DODGE CHALLENGER (1973 - 1974)
DODGE CHARGER (1973 - 1976)
DODGE CORONET (1973 - 1975)
DODGE DART (1973 - 1976)
DODGE DIPLOMAT (1977 - 1989)
DODGE MIRADA (1980 - 1983)
PLYMOUTH BARRACUDA (1973 - 1974)
PLYMOUTH CARAVELLE (1978 - 1985)
PLYMOUTH CUDA (1973 - 1974)
PLYMOUTH DUSTER (1973 - 1976)
PLYMOUTH FURY 1975
PLYMOUTH GRAN FURY (1982 - 1989)
PLYMOUTH SATELLITE (1973 - 1974)
PLYMOUTH SCAMP (1973 - 1976)
PLYMOUTH VALIANT (1973 - 1976)
PLYMOUTH VOLARE (1976 - 1980)