Solar assisted heat pump

[Tpm]

Newbie here looking for an answer I can't find on the web. If I bolted a water-to-air heat exchanger in front of the fan on an air-to-water heat pump, could I amp up my 24 tube solar thermal system enough to make an impact on central heat?

I'm looking to replace an electric tankless backup in a radiant-floor house
that is otherwise heated by passive solar, a wood stove boiler and 280 gallons of storage. The immediate reason to replace the tankless is the surcharge it places on winter vacations. But I am also looking to get a month off from stove duty on either end of the heating season plus a few sunny days off in between. (South central PA is not passive solar heaven.) The control is me. I consult Weather Underground every morning to gauge how soon I need to fire the stove. In optimal conditions for a heat pump, I'd flip a switch on a motorized three-way valve and divert solar from DHW to heat pump. If I can get storage to 140 degrees in daylight hours I'm good to go.

Stray facts. The solar system has a heat dump radiator. AC is a pair of air to air mini splits. A drain back system connects vented main storage with an 80-gallon dual hx solar tank so that the former backs up DHW.

A second question. I can buy a two-ton ATW heat pump on eBay in Britain for about $2,300 including shipping. Trouble is, it's 50 cycle rather than 60. I'd want time of day and set point control only. And a reliable compressor needless to say.