I would like to replace my current thermostat with a programmable one. I a have a multistge heat pump system and the thermostat has 6 wires going to it. Y G O R W2 and E. How do I decide which is the correct thermostat to use.

Make sure the product description specifically states it can be used with a heat pump. Ask somebody if you can. Also spend some time here looking at the trouble people are having, and avoid models that seem troublesome.