I have put 6-inch straight Kuryakyn risers with flat bars on my America, have a look at my gallery. They are super comfortable especially for my 6'3" frame. The cables are a little bit long visually, but no problems with operation.

TBA, Stainless extractors / drag pipes, 65mm over forward controls, Thruxton needles, 904cc, head ported, lowered 1-inch, Console removed, relocated battery box, Australia.