Sibson
Kev,
Go spin with Charlie at Sibson in the S2A. Do you realise how much more spinning you will acheive in that aircraft than you would for an hour in the Cessna - likewise Camb's Ea200 (but I do not personally know/therefore can't recommend their instructors).
My Pitts-biased opinion.
Do erect/inverted and then cross-overs - in either the Ea200 or the bipe.
HTH
Stik