Bagster do some smaller clip-on or magnetic tank bags. Have a look at the Handy which is also called Tweety if you go for a tank protector/universal harness. These bags are well made and wil last you years.
http://www.bagster.com/en/showroom.php?id=80
I have the Minea. Good size for camera, phone, specs case, chain wax mini tin, waterproof overtrousers and sun hat/wooly hat. Expands for touring. I had this on my SV before I changed bikes and had no problem with seeing the clocks or riding comfort.