Saw this (http://cgi.ebay.com/ebaymotors/Suzuki-Bandit-400-OEM-Windscreen-fairing-flyscreen_W0QQitemZ4566890146QQcategoryZ35583QQssPageNameZWDVWQQrdZ1QQcmdZViewItem) while browsing eBay this morning - it's off a Bandit 400, but I believe it will work on a GS just the same. I know a few people are looking for one of the OEM fairings, thought I'd point this out. Has the mounting hardware too, although you might have to play with it a bit for the GS.
That's the same fairing I have on my bike...see my avatar.