I have had several of them since they came out, and prefer the KingCat for it's larger size. It is just easier on the eyes for me.
A P-80 would be on the low end of the thrust scale for a KingCat. The recommended thrust for the KingCat is 19-35 pounds, and the P-80 does 22 lbs, which is the maximum thrust lever for the BobCat..
I had a BobCat XLwith 31 pounds back in the day, and it was blistering fast. That proved to be way too much engine for it, but it was structurally strong enough to take it. It is probably still flying somewhere in California right now.

The latest version being all composite is a clean, fast airframe that would be ideal with a P-80. Dustin's BobCat has loads of performance with a Jet Central Rabbit, with 22 lbs. Everyone he has buddy boxed on it is amazed at how well it flies. The composite versions features flaps, which are a great improvement over the original Standard and XL versions.
I am building a "Fly Navy" KingCat for a customer right now, and intend to build another one for myself soon. See the short field take off and landing by yours truly with my KC here: http://vimeo.com/19371854
It shows the type of slow flight performance the KC is capable of.
The field is 700' long, and I didn't use half of it. The white line across the runway is at the 350' mark. I turned it around short of that line.