I'm researching this myself, as I'd like to brighten the rear lights and reduce the electrical draw. The lower bulb has actually begun to melt the tail-light lens. The Motorrad setup looks fantastic, but $60+ is a bit too much right now.
Monte: Did you go with red or white LEDs in both plugs? I've read that it's best to use the same color LED as the lens but if I did that, the license plate will be illuminated red, which I don't want.
I was thinking of going with a white 1156 on the lower plug, and buying one of the fancy "flashing" LED brake bulbs for the top.