I have found the approach shoe style saftey trainers on this page to be the best wearing I have tried so far -
http://www.screwfix.com/app/sfd/cat/...31038&ts=63750
They may possibly be the same ones as the Dickies ones you have. I have seen the same shoes branded with different names.
There are now boots as well on the same page but I have no experience of them.