4" & 4.5" bolt patterns ... new wheel choices ?

Thanks ... discs on the front.
Then since you have K/H disc brakes, this sticky thread may help you for a low-cost 4.5 conversion without changing anything but the rotors. Then all 4 wheels are the same.
https://www.forabodiesonly.com/mopar/threads/using-mustang-rotors-for-4-5-bc.20544/