You might also like to try Sqn Ldr Vera Atkins (Sqn Officer in the WAAF, I think) who was part of F Section SOE. She was responsible for dispatching female agents to France, and, after the war, made it her personal goal to discover the fate of all those she sent out who didn't return, and bring those responsible for their murders to trial. Fascinating book about her called 'A Life In Secrets'. Great leadership, showing dedication to her 'girls' even after they had died.
One could argue though that her connection with the RAF was entirely an adminisrative exercise to obtain the necessary authority for her investigations - maybe prompted by the RAF/RCAF etc connections of some of "her" agents.
Spymistress: The Life of Vera Atkins, the Greatest Female Secret Agent of World War II is also well worth a read too, although I'm only half way through it, and I think "A Life in Secrets" is probably the better of the two.
As for the original question, I'd probably go for someone like (the recently passed away) Willie Tait, Cheshire or Bob Palmer.