I got some from the Kawasaki dealer and they're a perfect fit, thank you. I also ordered some from cycle to cycle at .80 each.If you want to stick to the original 'D' shaped orings (I think 1100's are), or the ACE option doesn't 'pan' out, you could try Kawasaki part #92055-1245...around $3.75 apiece.
Last week I did a carb clean on an 05 Kaw Concours (ZG1000). They're Kehein's and use 2 air cut valves on the outside carbs. I remember thinking how much the air cut orings looked like the ones on GL1100s. Unlike Honda, Kaw is really good about offering carb parts separately. The above part number is for that oring. I can't promise they're the same so maybe try one first.