Coachbuilders in Berkshire area?

[Oh Behave]

Was just wadering if anyone knew of or could recommend a good coachbuilder in the Berkshire or surrounding area. Reason being we have a horse lorry and today the horse tried to jump over the breast bar into the living quarters but luckily didn't quite make it - quite a common thing in rear facing lorries apparently. So we are thinking of getting some anti weave bars fitted, as the wife has lost confidence after todays little episode! I don't blame her tbh, as it scared the crap out of me too!

Thanks in advance.

N