Best RSS Reader for Linux? Bonus if it has PDF/epub export

Right now I use Read You on my phone to get RSS feeds and I read articles on my browser but I want to cut the time I stare at my phone throughout the day so I came up with this system:

Once a week I will look at all the feeds I follow on my PC RSS reader, select the ones I want to read during the next week and save them / export them (possibly in PDF or ePUB?) so that I can put them on my old Kindle (that has no internet access) and read them only using the kindle during the week.

This will drastically reduce the time I use my phone to first scroll and select articles and then to actually read them. Looking at a screen all day for work and also looking at a screen (phone) in my free time is not good for me and I want to change that.

If no RSS reader has that option, does anyone know of another program or firefox extension that would let me "export" web pages as pdfs or epubs?