My friends reply: Hi Steve,
I got my LED's from http://www.superbrightleds.com/
All of my bulbs face either forward or aft along the centerline of the car so I just got regular replacement bulbs.
I understand from James that some of the bulbs on the GTV face the side of the car. In that case they make a special bulb with a 90 degree base. Since LED's are directional you need to make sure they point in the direction you want the light to be seen from.
Also, they tell me you must use a bulb the same color as the lens. For some reason I guess the lens filters the light from a white LED and you won't be able to see it.
Hope this helps,