Changing AC split system compressor to Heat Pump

I recently purchased a house with a new (<6 mo) 3.5 ton split system AC and new A coil over an oil furnace. I'd like to switch to a Heat Pump. The compressor is an OXBOX (Trane) model J4AC4042A10000AA, and the interior A coil is an ADP model HE34142A170A0000AP. What's the simplest & least expensive way to make the change? Can the compressor be replaced and keep the existing A coil? What heat pump brands are compatible with that coil (it has a piston metering device with a TXV access port). Can an AC compressor ever be converted to a heat pump by adding a reversing valve?

source https://hvac-talk.com/vbb/threads/2243763-Changing-AC-split-system-compressor-to-Heat-Pump?goto=newpost