Since I converted the taillights on my TriGlide to LED, including the addition of a high-mount third brake light, I wanted to do something about the bulbs in the tourpak. The OEM tourpak bulbs are just your standard run-of-the-mill 1157 bulbs, acting as additional running lights and brake lights but lacking the instant-on performance and brightness of LED bulbs.
So I looked around for a plug-and-play replacement and found bulbs on that well-known auction site. The bulbs have 27 high-intensity "surface-mount device" (SMD) LEDs with six facing directly to the rear and the other 21 arranged in layers around the bulb. This produces light that's visible from all angles. (If you want the particular seller I bought from, send me a PM).
Although they took a while getting here, being shipped directly from China, I'm very satisfied with them. They produce very bright red illumination to the tourpak, especially from the sides, and being LED technology they provide that "instant on" performance as expected from an LED bulb. They are true plug-and-play and have no clearance issues whatsoever. They cost $23 for two bulbs with free shipping. You may be able to find similar bulbs in your local AutoZone, Pep Boys, or other automotive parts retailer but I never took the time to drive all over town to see.
I think this is a good bang-for-your-buck way to go without going overboard on cost.