The radial pitts is the lastest design and yeah I find her rather ugly.
You can find the pitts s1 in the electric and 40 size but in the larger scales you can't find them.
The Christen Eagle is a knock off of the pitts and they are even harder to find.
I think it's a hard design to model because of all the high stress it goes through during some of it's violent tumbles and stunts.