Whelen does make one with turn signals as well check it out here and its only around a hundred bucks. I first saw this on the back of a police bike in Ct and had to get one myself my only problem is where to mount it as I have an emergency flashing lightbar where everyone puts them and if I put it below it bloks the license plate pretty badly. But the thing is pretty bright
here is the link http://whelen.com/pb/Automotive/ProductSheets/Lightheads/StripLite_LED_Series.pdf