I have a 3 year old Goodman 2 ton heat pump.The inside air handler is ten years old and leaking at the a coil. I want to install a Nordyne 2 ton 13 sear air handler in place of the leaking air handler.This new nordyne air handler has a factory installed txv,which is what I think that I would like to have.The outside unit is a 10 seer. A/C installer says that I need to go back with a Goodman and let him install a txv on it,or just use the correct piston.I was thinking that later on I would replace the outside unit with a 2 ton Nordyne .I have not been happy with Goodman .AC people say that it would be a mistake to mix this parts .My question is does it really matter that much.I live in SC around Myrtle Beach,with its weather conditions,some cold days in the winter (around 25 low but mostly30s,summer hot high 90s to 100 with wet humidity Thank you for any information that will point me in the right direction.

\have it professionally replaced and let them figure out what id best. A TXV is always good to have since it will meter the refrigerant with more accuracy.

Thank you for your answer .I should have added that one a/c man that says I should not mismatch the brands sells only Goodman.The other a/c man sells other brands and not Goodman ,but is bragged on by a lot of customer .It gets confusing out here in consumer land.