69 dodge dart disk brakes

A possible combination using most of the parts you have now include the Dart control arms, using the spacers at this link, which allow the smaller ball joints in the Dart upper control arms to fit the B-body spindles.
Mopar A-Body Upper Ball Joint Tapered Adapter
You could also swap the upper control arms to A-Body parts for '73 and newer that have the larger ball joints. Dr Diff has good prices on new ones ready to install.
You should then be able to use from your B-body parts the lower ball joints, spindle, rotors, calipers, caliper brackets, etc. I'm not sure about the hoses, you might need to investigate that.
If you have a sway bar, it may hit the caliper. Swapping the spindles side to side will move the caliper rearward, but you may encounter other interference.
This swap will gain you little braking ability, if any at all. It would get you the 4.5" lug pattern, if that's what you're looking to do.
There are lots of resources out there for you to read about swaps like this.