What should I look for when buying a horsebox lorry?

Type of chassis: a good starting point for the average horsebox is the Ford Cargo 0811 or 0813 models, or the Leyland Roadrunner 8-12 or 8-13. Both are reliable, have good turning circles, although both are best with 6 cylinder engines.

Taken from http://www.world.co.uk/faq/horse.html