Any modern set that meets BS standards, or is e-marked should be up-to-scratch safety wise. Thereafter, failing the "classic looks" issue, I'd suggest
choosing the ones that feel most comfortable.
For classic type belts, or even belts made up to your spec, I have heard that Quick Fit of Stanmore are very good. NOT to be confused with Kwik Fit in
any way.
Their website is not yet finished, but does at least show contact details:
http://www.quickfitsbs.co.uk/default.asp