horns have always intrigued me, since i heard the jadis eurythmie's at the '96 s'phile show in nyc, & more recently, the original wersion of the avantgarde duo's. i'm not yet ready to give up on my conwentional set-up, tho, 'til i get to try the newform research ribbons! ;~)
that said, i'd start here, and look at the oris 150, the oris 200, & the hedlund horn. also, i'd consider the aer drivers instead of the lowthers.
http://www.bd-design.nl/wwwpages/main.html
hope this helps, doug s.