I guess it also depends upon how you define 'Thrust Vectoring'. P.1241 was to have RALS. Does a Remote Augmented Lift System (or, for that matter, an Ejector Lift Engine System) qualify as 'Thrust Vectoring'? If so, our list can be grown. (I've included the P.1243 based on its vectoring nozzle.)
From the old Harrier.org site (but slightly reorganized):
A comprehensive list of the V/STOL combat aircraft design projects undertaken at Kingston in the years 1957-1988
web.archive.org
P.1227 - 1984-85
Harrier II development
- 1 x
Pegasus
-- Bigger wing with integral tank/weapons module ahead of outriggers.
P.1228 - 1985 vectored thrust, supersonic canard naval V/STOL strike fighter
- 1 x Plenum Chamber Burning (PCB) engine
-- To NST.6464, resembled McDonnell-Douglas MDC 279-3
P.1229 - 1985 supersonic, four nozzle, vectored thrust V/STOL fighter
- 1 x RB.533 or
Pegasus-type
-- Engine was 'dry', no PCB etc. fitted. To NST.6464
P.1230 - 1985-88 four nozzle, vectored thrust V/STOL fighter
- 1 x RB.422 or other four-poster PCB engine
-- To NST.6464, design by Brough/Kingston/ Warton team
P.1231 1985 supersonic
Harrier II development
- 1 x
Pegasus PCB
P.1232 - 1985
Sea Harrier/GR.Mk.5 development
- 1 x
Pegasus
--
Sea Harrier FRS.Mk.2 forward fuselage and wing with
Harrier GR.Mk.5 rear fuselage
P.1237 - 1986 ASTOVL with RALS
-- ASTOL = Advanced Short Takeoff and Landing
-- RALS == Remote Augmented Lift System
P.1240 - 1987 Stealth ASTOVL, swept wing with tip fins
- 1 x vectored thrust reverse engine installation
P.1241 - 1987 Stealth ASTOVL with RALS, delta wing, dorsal intake
- 1 x RALS
P.1243 1988 Ramp-launched, tail-sitting recovery unmanned fighter, tailless delta
- 1 x Williams turbofan
P.1244 - 1988 P.1227-3 development
- 1 x
Pegasus
P.1245 - 1988 P.1231 without PCB
- 1 x
Pegasus
P.1246 - 1988 P.1245 with PCB
- 1 x
Pegasus PCB