You could always do the giant cyclerack LED brake mod. It has two levels of intensity for running and brake. Hook up two wires and your done electrical wise. I'm using a led lamp in the stock brake light as well. If you go the route of having your rear turn signals doing double duty keep an eye out for a filament burning out or else it will look like you have a non blinky turn signal on to anyone behind you.
Running lights only
1 = Cyclerack
1= LED trailer center brake light http://www.fisheries...km=on&km=entire or http://www.amazon.co...r/dp/B002L9D7MQ
2 Cushion Clamps http://www.fisheries...km=on&km=entire
a couple of nuts and bolts to hold the clamps on.
Wire it in to the harness behind your stock brake light and presto,,,,,
Note: my mod won't work if you have or plan on putting a kolpin fuel can mount on the back of the bike.
Hodakaguy's low mount led brakelight mod he whipped up pictured below