Hi there!

I have been using a very basic Amazon Kindle for reading books and it suffices. I don't need any special. But recently I got into reading graphical novels, manga especially and I know there is a ton of them online, together with fanfics, etc. That made me wonder, is there a reader setup for comfortable reading comics? I would be interested in that but I am not sure how to look and where to look for it.
I love my eink reader, but for comics, I either read on my Surface or my Samsung 12.2" tablet.

Manga being black and white is a different story. The Kobo Libra would likely make a nice manga reader, though storage is limited compared to a tablet and I'm not sure about reading stuff online.
An Onyx Boox Nova 2/3 is probably ideal for manga. Similar size to source and runs the best manga software e.g. Tachiyomi.

For graphic novels, 13" B&W devices like the Boox Max have been the best e-ink could offer. But 10" colour e-ink devices have just started appearing in China, so something better could be on the way fairly soon.
I use a reasonably priced 10" Lenovo tablet for reading comics. Works great. (Tab M10 FHD 2nd Edition.)
I'd also suggest getting an 8 or 10 inch tablet. Depending on your use cases, either get a cheap one like Amazon fire tablet or something more powerful lik a Samsung galaxy tab / iPad.
Yes, for colour anyway, my Lenovo 10" Tab (about €120) is best. Though comics do work on the 7.8" Likebook Mars. Configurable contrast. The Kobo Libra (7") is a shade too small and more awkward.
Lenovo seems to make the best cheap Android tablets. I've had a Lenovo Tab2 A10-70 for four or five years that is still as good as new. If it gave up the ghost suddenly, I'd likely replace it with the Tab M10.

For reading comics, I use my Surface, which has a 12" screen. The screen is about the same size or slightly larger than a standard US comic page. And its 3:2 screen ratio seems to fit a comic page better than an iPad's 4:3 or Android 10:16 (though Android seems to have the best comic readers for CBZ/CBR files, in my opinion).
The Pocketbook Color might interest you
I've tried it and it's too small for comics.
Maybe the new (not yet released) 7.8" version will work better.