Hi! While I am the poster of that other thread's material, I may not have covered all your questions in that thread.
1. Brookstone iConvert
2. $99 USD
3. Both grayscale and color
4. Max width is a tiny bit over 8.5 inches (21.6 cm) the standard width US Letter sized paper (roughly equivalent to A4). Length is near indefinite far as I can tell, possibly limited by memory. It can definitely do longer than "Legal."
5. Two AA batteries
6. Stores directly to MicroSD (sold separately). Operates completely independently without being connected to anything. You can connect to any comptuer via a mini-USB port, but I prefer to just pop the MicroSD chip out and put it in a reader or adapter. If you use an MicroSD to SD adapter (which often are sold together), you can put it right in the eDGe's SD card slot.

Also, Brookstone does ship to the UK if you buy online.

Personally, I love this thing! It is the only doc scanner I know of that operates by itself without a computer. Using a handheld always takes practice to get right, so I often make multiple passes over the same document to be sure. It's quick, but takes a steady hand and cleared, flat surface to get the most out of it.

Like I mentioned in the other thread, I often have to use it to scan medical records or journal articles in a secure area where there is no copier, and setting up a laptop for one page would a major waste, not to mention an extra 8-12 pounds of gear to carry for that one task. I take my eDGe along to check the quality of the scans, and use PhotoShop Express to do quick adjustments like contrast and cropping. Here's the thing though: All scans are stored in JPG. If you want PDF and/or OCR, you'd have to put the file on a computer that has that kind of software and handle that separately. If you go from scanner to edge, I don't think there is a way to display a JPG on the eInk side unless I'm forgetting something. There might be Android software that converts to PDF, but I don't know of any that does OCR.