I believe that there are only two S2As on Permits; all other two seat Pitts are C of A = expensive! Eagles are on Permit but there are a limited number in the UK though I think there are two for sale at present between about £50 and £75k.
Jungmann seem to come up rarely; are not Stampes on the point of going over to Permit? If so it may pay to wait a while.
I can't see why you would choose C of A over Permit these days with the range available on Permit.