Doepfer

I think the depth problem will be a challenge with most cases made  
for mixers. The best working solution will probably be a Portable  
case and a stand to make it lean back at the angle you want. There  
are some good acoustic guitar stands that work well for the portable  
cases. Ones with this type of design:
http://www.amazon.com/gp/product/B000JC495Q
or this
http://www.jcpenney.com/jcp/X6.aspx? 
DeptID=58200&CatID=58200&Grptyp=PRD&ItemId=1352a54

both for under $20.

-James