Honestly, I do not have any idea what I would do if everything works out.
If the head is bad, here is a remanufactured one:
https://www.summitracing.com/parts/vre-2538/overview/
Car-part.com shows an HX head for $150 in Phoenix, one for $163.35 in Yuma, and one in Tucson for $300. I cannot find any heads through LKQ, but it only seems to show whether they have the inventory at that location. RockAuto has a head for $475.77 shipped.
RockAuto. Yay.
Jegs has one for $620.
https://cylinderhead.com has one for $350 (+ shipping). AutoZone has one for $580.
I do not know how much another D16Y5 engine would cost, but it would be far more complicated than just the head, and I am sure that would be the end of this project.