I have a bit of advice for you. Before anybody comes out and while you are making your flurry of phone calls. Tell the person on the other end of the phone exactly what you are wanting done. Tell them that unless they are willing to do exactly what you want, with appropriate testing equipment, you are not going to pay them. That should weed out a fair amount of company's. I will warn you that whichever company comes out, is going to be far from cheap. You will probably pay a pretty decent amount of money for that to happen and I would imagine they will spend a fair amount of time there which will translate into $$$ out of your pocket. They are probably going to make recommendations which are also going to be pricey. If you are unwilling to pay for those recommendations, I wouldn't even bother calling them. It sounds like the issues you have can very possibly be quite expensive. Just be prepared ahead of time.