Hi there Daniel. The C-18 bags are the same thing as the c-19/Q bags, just a little bigger but they should fit. They are HEPA cloth graded which is what I would highly recommend using for your Panasonic. The C-5 bags are made out of paper which are not as good as the cloth bags.
Regarding the filters, yes they should be identical to either the Kenmore EF-9 or the EF-11 filter. I can't fully confirm but alot of the Kenmores uses filters that are similar to the Panasonics.
Hope this has helped.
