Not trying to be a total ass , BUT why the need to convert to discs ? Front disc brakes make sense, they do the lion's share of the work
stopping your crap. For parking Rear drum brakes actually have enough braking force leverage to hold the Jeep on a steeper hill.
Also, isn't the main function of the mechanical brake is to be an, " Emergency Brake " that will stop the Jeep if / when you lose hydraulics ?
I know my 99 TJ with drums will LOCK the rear wheels at 30 on pavement, (Scary as hell by the way).
My wife's 04 TJ with OEM rear discs and E-brake in the hat style rotor will slow down at 20 on dirt without locking the wheels.
It would be a candidate for a participation trophy. Maybe for the Florida boys running in swamp mud disc may be easier to wash out,
but us mountain boys need a brake with enough leverage to hold your crap on the mountain or stop you in an " O Shit scenario ".
I know I can only brag about one of our Jeeps having the magic of 4 wheel disc brakes, but I also know which Jeep works a little better in my real world situation.