I am looking for a handlebar bag for a cross country tour. I looked at bags by Avenir and Topeak but both were mounted rather high or the bags themselves stood high... The Ortliebs looked to be a little better in this regard but if possible I would want something even lower. Are there bags that are almost flush with the handlebar? For a cross country tour should I have a medium or large bag? What else should I look for in a handlebar bag?

Thanks,

-Mike