Hi & welcome to MR.
If you want to check out different readers, have a look at the
matrix in wiki.
Me personally I am quite happy with the 6" on my Sony. Thought initially it's too small but no, it works fine.
Also check out the
eBook library from MR. Sooooo many free books, lovingly formatted by MR members. That'll keep you reading for a while.
And don't forget to look into the
Lounge if you want some fun.
But that's not all of course - so many subforums to view and so many things to discover.