Hi Richard,
This is a bit of a tough one to answer I think, its not my period at all but I can venture a few comments which will hopefully help you in further research.
Late period spathas and Germanic migration swords would be what you are looking for I think.
Patrick Barta is a smith who has done quite a few pieces from this period and is generally acknowledged as working to a very high historical standard. You may find his website interesting:
http://www.templ.net/english/weapons...middle_age.php
Best regards,
Iain