New Head Gaskets Major Problems

[BHP]

HI my name is Glenn and i am new to this forum unfortunately not a good first post but here goes
Purchased the isuzu vehi cross approx 4 months ago private sale the guy was imigrating test drove the car and had a good look over it all seemed ok.
a week later did a 300 mile trip noticed the temp guage starting to rise half way into the journey stopped and checked the obvious water had gone right down in the expansion tank,so topped up and proceeded with caution stopping at regular intervals no more overheat but water slowly going down.
car booked into a garage first possible oppurtunity there assessment was that the rad was partially blocked and that the oil cooler which is built into the rad was leaking allowing water into the oil easy to rectify.
The rad was taken to a specialist as could not source a rad for it here in the uk he said the intercooler was fine and the core blocked therefore the oil had to be because the head gasket had blown.
Strip down time.
Rebuild time today
Could not get the engine started compressions checked 1,3,5 170 2,4,6 30 they said its the valves hydrauliced no probs unfortunately they connected a battery charger to the battery whilst trying to start the vehicle and melted something to such an extent that the neutral became live and the starter would not disengage the reason behind this post is i fear they would have now blown the ecu and am preparing myself for the worst case scenario.
Knowing the availability of parts for this vehicle in this country was wondering if any one new of a breakers where i might possibly be able to obtain one.
Anyone heard or come across this kind of incident before all advice appreciated.
Thanks in advance Glenn