I know that standard advice is that you need a ruler foot and thicker rulers, but while doing some practice FMQ work (on my domestic sewing machine), I recently experimented with using my cutting ruler with my floating (Not hopping!) quilting foot, and it seemed to work well for me. The important thing seems to be that my foot is low enough that the ruler does not seem to be able to get under the foot. (I've heard more than one long arm quilter say that if the ruler *does* get under the foot (and the needle then hits it), the noise is *very* scary and startling!)
If you want to see how to convert a hopping foot into a floating foot, Leah Day has instructions
here.