After a couple of days research, asking questions on the Prepar3D forum and reading/watching some of
the resources I've linked to here, I came up with a solution which satisfied my requirement of a convincing representation of the fast jet terrain hugging flight profile.
Cruise ~ 450 kts
Three variants in the fleet: A = conventional takeoff and landing, B = S/VTOL, C = carrier. | Livery by Donka. | Fun to fly, especially S/VTOL in the B model. DO NOT get below 200 knots, which can come on suddenly around the circuit. Absolutely beautifully modelled by India FoxTecho. I had their F-35 for P3D, and this one is even nicer. It's also frame rate friendly.