I can't seem to find anything much bigger. Would scanning the cartridges themselves be of any use?
1200DPI moire removed might work.
Is 2400dpi alright? My computer kept crashing at 1200dpi because my printer kept trying to load it into its own proprietary image editing software, but at 2400dpi it prompted me that the scan was too large and it just let me save it to a file, bypassing the software.
Obviously, I didn't get to apply the Despeckle filter because of this. (I'm assuming that's what you mean by "moire removed")