Yes, thats '08-'10 XBS (Lightning) and XBR (Firebolts). Theres plenty of recyclers on eBay that part out bikes, try there? It might be easier (and less wasteful) than taking apart a running 'late model' Buell.
It looks like you just put a carb on them anyway, why not use a 1200 sportster? They made a LOT more of those.
Good luck!