DC10:
Problem there is if he really wants to go DCT to Southend he'll be busy in the short time from EGSC to Stansted CTA, negotiating a transit over Duxford, where this time of the year, they have all sorts of stuff screaming about in their overhead.
Best to avoid Stansted altogether and go round to the north IMHO: he can always descend to 1400ft and nip under the space south of Haverhill, but then he'll have the gliding at Wethersfield to contend with.
Cusco