SBP DISC to LBP DISC SWAP- 72 Swinger

Looking to swap my 5x4 front disc to a 5x4.5 front disc set up. Would I need upper control arms for the swap? I have spoken to two companies offering front brake kits for 900.00 and they can't tell me what I specifically need because the kits were made for DRUM to Disc conversions. Please help with any info you guys may have because I've read these forums to death and can't find the answer to my question. I'm thinking I need spindles, calipers, rotors, bearings, and seals, prop valve and power booster(going power). Do I need Upper arms?
Any good avenues for kits like this? Thanks a mill to all of you for answering!

-Paul