Southport have had a truck class all season, I know this is a bit far though. I did hear a rumour that one of the North East clubs were going to give them a go aswell, I think either Bately or York? Not sure though.
Best thing might be to go to which ever club is local to you and drum up the support for trucks. Personally, I think the trucks have been the highlight class of the year. They are cheap (£129 for a new T4), tough and as fast as the 4wds on most days.