I had the GS-Air lights on my PulsarXP. They were pretty good, although I don't think they are as bright as the Lumiled LEDs that are used by some folks who roll their own. The only problem I had with the GS Air setup was that the plastic covers turned a hazy-yellow after being in the sun for a year. I would think that a higher quality plastic/plexi wouldn't do that. But they were a decent setup for the money.
As far as building your own, it's pretty easy and very inexpensive. Mirrored plexi on eBay was about $12, Lumileds were about $25. The help I got from someone else on this board for a wiring diagram was invaluable (I won't name him unless he approves). Another local builder and I hooked them up to a 12V DC power supply and they are BRIGHT. I'm only using 4 LEDS per side. The hardest part was shaping the mirrored plexi to fit my wingtips.