ECU driving me to drink

Hi , ive fitted a 5.7 and rfe545 from an 07 ram into a 1948 chrysler .Its completely stock and is running a hotwire harness and 05 ram ecu.
Ive been driving it since easter with varying issues.
The original ecu from hotwire runs perfectly but must have a dry joint or something as when it gets hot the car will not re start until it cools down then runs perfectly.
So i ordered another ecu from hotwire that would crank the car but nothing else.So returned that one which tested ok when he got it back?
I then spoke to B&G Chrysler and bought an 07 ECU which they re programmed to run stand alone. They sent me 2 because they werent sure if the first was going to work. They were right , neither of them run the car properly.1 runs good but the car goes into limp mode (no throttle response)when you go up a hill , the other has erratic rpm and will go into limp mode idle while testing it in the shed. Unfortunately these run on canbuss so my OBD scan tool wont read them through the hotwire harness.
I ordered another reco off ebay in sheer desperation but that one will not do anything but crank also.
where do I go from here?
Ive got 4 ecu's that all have different faults when you install them.........
can i use a diablosport thing to take the tune from the dry joint one and put it into the no go one?
Is there someone in the usa that can do this for me ?
Is there anyone that answers emails in the usa at all? (Im in australia)
Should i give up and spend a heap of cash to go aftermarket for a stock engine?
Im out of ideas , HELP !!!!!!!!!