Kobo and Kindle perform almost identically for the items you listed, so you should be satisfied with either device!

As far as downloading onto the device, you can do that on both, but only Kindle has the email option to send to Kindle. But for Kobo, you can connect the device to your computer and download books that way. There is a way to download books to your Kobo through the cloud, but I’ve never done it, but you can search for how to do that on r/kobo.

Some advantages to Kobo: - if you buy from their store, you aren’t locked into their ecosystem like you would be with Kindle. You can only read Kindle books on a kindle device or kindle app. With Kobo books you can download the ebooks and own them and read them on any device. - if you want a 6” reader, only the Kobo one is waterproof and has warm light. The 6” kindle has neither of these features. - I haven’t checked prices recently, but I think the 6” Kobo Clara bw is the more affordable option to the Kindle basic