Thanks
The size is not a problem, I have to reduce it to 800/600 or sometimes 1000/750 for more detail, but that's the largest I'd go for the wiki as it doesn't autoresize for bigger pictures.
The watermark shouldn't be a problem I think. Might be better with it with some eBay guys "borrowing" wiki pictures for their auctions.
We were discussing at some pint to add a MTO or SAKwiki watermark to all the pictures, but I think the current software we're using prohibits that.