Hi Julian,
Many thanks for your suggestion, most helpful in narrowing down the options. Hopefully I'll get a few more suggestions.
I too have had brakes added to my CLH trailer (by CLH) and they came with larger wheels. From Kent I have trailed up to Scotland, across to Wales and Cornwall along with a number of places closer to home and I have not had any problems though I would agree it does not look/feel the most robust of trailers.
As an aside and at the risk of taking this post off direction do you use a strap, cable or rope on the winch?