Recently there have been a couple of UK tournaments that have used a "banding" system. I'd been curious about the particulars and my patience was rewarded when somebody posted a link that explained how it works. Looking it over, it is similar to one of the suggestions that was floated in one of the post BsB discussions. Read for yourself here:
http://www.coldark.co.uk/tngforums/forums/thread-view.asp?tid=1626&posts=1#M19499Using that system for initial draws, and then including opponent provided scores seems like a reasonable approach to me.
Interestingly, the army raters are also participating in the event.