Jules will be able to advise - he know his commers and his stock!
I recommend one of these up high... like peepers
http://www.ratsport.com/PBSCProduct.asp?ItmID=9611658
If you use this zoomed image you can see it nice and high
http://www.flickr.com/photos/johnyboy/7955002232/sizes/k/in/photostream/
I use it more than the "normal" wing mirror