Current 'best' aftermarket non ac heater core?

I have local radiator shops.. they charge the same as Glen Ray but I don't know much about them and don't want to gamble.
If a local radiator shop is still in business, they've got to be decent. They used to be everywhere, but with the cheap overseas stuff available it's been cheaper to throw away and buy new for quite a while. To still be surviving by fixing radiators, they must have their act together. The few I know of also do general repair though.