Filter Questions (XS-Pro and case recommendation)

I am getting ready for my first ND and Polarizing filter purchase. I have been reading a lot of the postings here so I think I am just down to a few minor questions.

I am looking at starting with the B+W 77mm 3-stop and 6-stop ND filters as well as the 77mm Kaesemann XS-Pro Circular Polarizer filter.

First Question - The XS-Pro gives a warning about the outside diameter size and some lens hoods may not fit. Do I need to be concerned with my EF-S 17-55mm f/2.8? Also down the road if I go full frame, I would most likely end up with the EF 24-105 f/4L and EF 17-40 f/4L.

Second Question - recommendations for filter cases to hold said filters? Something to hold 3 to 4 filters. Generally, I would be putting the filter holder into my camera backpack when I am out using them. Anything better than the plastic cases they come in?

Thanks!
Eric

1) No, ignore the warning - the hoods will fit just fine.

2) I use B+W E1 pouches for individual filters. Says up to 77mm, but they hold B+W 82mm filters just fine.

Thanks neuro. I have been looking at those pouches as well ones like Tamrac MX-S5363. I just have that fear of picking a cheap holder and scratching the filter.

This would potentially have me stacking an ND Filter (f-pro) and CPL (xs-pro). I read neuro's thread on stacking and thought the 2 might be tolerable for my hobbyist purposes. It did steer towards looking at the xs-pro for the CPL rather than the standard one.

I am on a crop body now, but always try to think through my upgrade plan which would be EF 17-40 f/4L if I wanted wide on a full frame. I leaned towards the xs-pro for the cost and front threads for a lens cap. Should I think a little more about going with the slim CPL instead?

The XS-Pro CPL is actually thinner than the Slim CPL (4mm vs. 5mm). I bought the Slim Käsemann CPLs (77mm and 82mm) before they were available in the XS-Pro mount, today that's what I'd get.