I'm also looking for my first reader and I want it to be bigger than 6. From what I read and watched in the last month, we have very few options.
Onyx i86 ML Plus, which has Android and more RAM, but it has bigger border around the screen and
bad ghosting when dragging. It's also more expensive.
Pocketbook Inkpad 840 - better quality casing, smaller border, no Anroid. Could not find any good reviews.
Icarus Illumina XL - Will be released soon and can be preordered now. Android, small border, dual core processor. The only downside is lower resolution. From what I see, the people behind it are really open and give straigth answers, which is a plus for me. I think there will be a video of it soon.
Maybe you also can go for Kobo Aura H2O - 6.8 inch, no Android, good dragging / zooming, better/newer screen.
You can go watch or read reviews of the devices. I hope this helps you, I have almost made my decision.