Diesel Bombers - Reman or Repair? 7.3L with Gas in Engine

Vehicle: Ford E-350 with heavy-duty tranny and 7.3L Powerstroke, Manufactured in June 1999. :bat:

Hello,

I live in a state that doesn't let me pump my own fuel. Well, after 13 years the dreaded thing happened! A fuel attendant put gasoline in my diesel and I didn't notice it until too late. There was about 1/4 tank diesel already in the van and 3/4 tank gas was added by the attendant. Drove it about 15 miles, mostly highway. White smoke and a little rough running but thought perhaps it is just I need to check for water in the fuel line (I pull something and water comes out). Came home. Van sat overnight. Started up just fine but with white smoke. Drove 4-5 blocks and although never died it had no power, was shaking and billowing profusely white smoke. Checked for water in line (not sure if this is correct term but pulled something to let excess water out of line, if any). I can't smell very well and it seemed to keep coming...Closed it even though it was still running. Tried engine again. My 10 year old tells me that water is still coming out onto ground. I don't believe him because I know I closed the pull stick. Ground is wet. (I can't smell well). Tried again. No good. Called to have van towed. Mechanic couldn't look at it until Wednesday. He called and asked where I got my fuel last. I told him. It was then that he told me it was full of gasoline, not diesel. Also informed me that fuel is spurting profusely from under air-intake housing. Car running VERY rough with no power. He reccommended pulling and cleaning tank, replacing head gasket and a few other gaskets, oil change...However, I'm concerned about damage to pistons, injectors, internal chambers, etc. I just spent $5000 on the engine and fuel system to prepare the car for the next 10-15 years....We have 3 kids on the autism spectrum and need the space for them due to sensory issues. The responsible party (the gas station owner) says they take responsiblity...but want me to sign a release before they'll pay for what needs to be done.....SO, do I get the car "repaired" and take my chances that there is no hidden damage or that the life of the engine isn't reduced....OR, do I ask for a remanufactued engine, or ???? What should I have checked and/or repaired. This is a one owner car that I have had a lifetime oil change service plan on...and have been faiithful to care for the car for the last 13.5 years....The car has been the best we've ever owned.....we can't afford for it to become our "problem child" later due to hidden or unknown damage. What would you reccommend? What would you want to make sure was done? What tests would you perform on the engine prior to agreeing that everything is fine?