Can anyone in dallas recommend a good AC guy

I have to install two air handlers, one 3.5 tons, one 2.5 tons, plus replace the copper lines.

Got two quotes, one from a chinese, one from an american

chinese charge labor 3000, american charge labor 3500

i searched internet, for goodman airhandler, 3.5 ton price 579, 2.5 ton price 471.

Just feel they are two expensive.

Anyone in Dallas can you please recommend a good AC guy