2000 dodge durango 127,000 miles

Over the last 300 miles I've had to replace radiator hoses first then water pump then the radiator started squirting now when it been on the road it's computer shuts off and the factory security system shuts everything off since dodge no longer manufactures the computer I'm in one heck of a situation the mechanic that ran the diagnosis on it said his computer guy in Texas doesn't have any I asked him about the online dealers he told me he purchased 3 different ones Ebay from NEAT in Florida and another one I don't have the list on me and even though he gave the VIN# and the part none would start my rig so my situation is I paid $150.00 to have it checked and to see what it would cost if the guy in Texas had the part it would run me $900.00 plus $200.00 to have it programmed then $100.00 for him to plug it in does anyone have anyone to recommend for this I just. got a message from someone who said I could have mine rebuilt or exchanged for same part just need VIN# MILEAGE and part number the price goes from $249.00 plus tax shipping and core to $975.00 + the same has anyone had this problem please suggestion and recommendations will be greatly appreciated