OK, found the options in the Allon White website.
New 4/4 with 1.6 Sigma (not sure which gearbox) specced with five 5x15 s/s wire wheels, all remainder of spec left standard, including leather, painted dash, and vinyl easy-up hood, grand total £34431.
New plus 4 with 2.0 Duratec and Mazda box, specced with the same five 5x15 s/s wires, which defines the narrow body version, everything else standard as per the 4/4, total cost £37461.
So £3k extra for the 2.0 Duratec in a narrow body, seems quite a lot to me.
Nigel