You could try looking for a replacement top triple clamp and/or bar mount risers, or go to the local bicycle store and get a BMX style handlebar. The rise on the BMX handlebars are quite a bit more than motorcycle bars. You will probably have to get a longer throttle cable though.
The raised handlebars that you're talking about are from Barr Competition. I'm not sure the web site, however, if you go to www.ktmtalk.com there'll be someone to help you in the mini chat general discussion.