Thanks Julian,It turns out that Southern GT is no more but think AK sports cars seem to have taken them over, so I contacted them and they can offer a linkage and gear lever and gate and have spoken to Tornado too.
Both look possible as a starting point, but of course my set up is as Renault Alpine A310 and GTA,so would need some modifications.I know the GTD shift gate looked exactly what I wanted as the positions for the gears is exactly as mine is at present with the awful cable change.
I am trying to buy a complete GTA set up if this comes off it could be adapted and also won't be the eye watering cost of the Other two especially the AK version.
Thanks again for your reply
John