I bought mine from another dealer but I found them online at Sierra BWM: brackets alone $50; PIAA X1100 and brackets, $320
In reply ... The X1100's are rock solid as are PIAA mounts for the GS, no shake. As to the lights, I moved these lights from my 1150 after 7 years of use. Beaware these lights are good for being seen. That's what I've been using them for. If you're looking for some high output focused light for night time speed ... go HID. Oh yeah, the mounts alow the lights to be fully adjustable.