Northolt
What Type of aircraft are thinking of operating? Hangar space is at a min and the operating regime under military is often complex, limited hours of operations and during special movements very restrictive. Northolt offers great access to london.
We was based at EGLF and would ferry in to pick up PAX etc. depending on your Aircraft size have you thought of Oxford or Biggin Hill. EGLF is expensive as is Luton?