If the oil in the pan is full of metal particles, the entire engine is full of metal particles. IMHO it would be cheaper for the ESP company to just buy a long block versus completely tear down, clean, inspect, and replace all the damaged parts. If they tell you they only plan to flush the pan and replace the lifters, you need to immediately go over the local rep's head to the folks in the home office with the authority to do the right thing. If they continue to resist doing the right thing, you need to protect yourself legally. In other words, hope for the best but be prepared for the worst.
Jerry