Thank you for the responses.
It turns out that the store did not have any iRiver readers, despite advertising such on their website.
I ended up getting a Bookeen Cybook Gen 3. It is not ideal for PDF, but I like reading fiction too and am well impressed by how well that works. It is my first exposure to E Ink
and I was quite amazed. I imagine this is a common reaction from newbies, such as myself, and I will no doubt get to the stage where I regret my purchase and realise that I should have bought xyz instead.
In the meantime, I will try to enjoy reading, which is why I spent the money in the first place.