Front/rear suspension options?

If I understand you correctly, forget about the oem mounts and make a plate bolted to the front of the motor and welded/bolted to the forward frame extensions?
Or connect underneath to the K frame?
Do you use a mid mount, between the motor and trans?
I did plan to move the motor back as much as possible.
You could do either, make some mounts to the k member or front engine plate, yes on the mid plate if you do the front engine plate.
I didn't move my engine back so I can't advise on that but you can.