What heat pump did you get? I wanted to get a heat pump, but I ultimately ended up just buying AC. I was told it was not possible to pair with an existing furnace because heat pump control systems were proprietary and incompatible with a standard furnace control.
OTOH, a few months ago my stepmother installed minisplits after getting quoted $22K to install a whole-home forced air heat pump (going from no forced air at all, so part of that cost was ducting, though it's a single story ranch house so not terribly difficult).
Somewhere between those two points, prices went insane.