I found these Kool inexpensive risers on eBay. They are 7" tall but 5.5" from mount to handle bar with 1.5" pull back. They look awesome and bring your bars back 2.5" to 2.75" depending on angle. The stock risers are 3". I have ridden a short ride and they are much more comfortable for me so far. The stock cables are more than ample and not stretched at all with original routes. You could go a bit further but not much without the brake cable being too tight. http://www.ebay.com/itm/151395550619...%3AMEBIDX%3AIT
I love them. The finish is perfect and the additional pullback is ideal. This is the least expensive mod you can do to the bars for the best results. This should have been stock in my opinion. Still gives a drag bar look similar to stock bars but is much more comfortable.