I believe more shopping around could be good for you, but I do understand wanting to buy tires from a local guy you know.

If your going to stick with your local guy, I'd pay the extra for the Coopers as well. Maybe you should ask him what he recommends, he has likely sold more tires recently then I have ever bought. He has apparently sold the Chinese tires before, but maybe he is just trying to get you the lowest price he can find your size tires in. Just because he offered, it doesn't mean that is what he would recommend. If you trust him, trust him on this as well.

Tires are going to get tougher and tougher to get over the next couple of years, investing in better quality might be a good idea these days.