The highest BTU heat pump I see is 46,000 - that's not going to be a solution for a lot of homes, which need 30,000 / 1000 sq ft, not to mention loss in efficiency as the heat drops so you're getting less than that when you need it the most.
When looking at bang-for-buck / value / ROI, better insulation and air sealing should be done first. If you can reduce the number of your blower door test, then you'll have to spend less on running capacity (and their related costs).
