Interesting thoughts all!
Chaos warriors do have the looks to turn them into teutogen guard but they lack the dynamic poses.
If you like the current greatswords you can turn them into awesome greathammerers with the chaos warriors hammers and very little effort (see pic)
It wouldn't be to difficult to give them capes, white wolf iconography and heads and bitsfrom the marauder horsemen, white wolf sprue and space wolfs to 'ulricify' them
alternatlivly flaggelants lower torsos with full plate sculpted over them would look very good as well. and the one big hammer from the white wolf sprue with a beefed up hammerhead looks good as well.
now that I think on it I would consider using greatswords arms and torsos, with chaos warriors hammers, lower torsos from flaggelants or dark angels (like my warrior priest shown above) with plate mail sculpted over and heads from marauder horsemen and space wolfs and a collection of wolf cloaks and sculpted cloaks