I am in need of 2 custom document types. However, they are both just small tweaks on existing ones. Specifically, if I could just add a couple of fields to the following standard document types...

1. Page (menu item)
2. News

...then I would be fine. I know I can do this because I have already done it and everything is working great.

My question is, should be doing this? Or should I create all new document types that are identical to these and then add my extra fields to those? I am concerned about upgrades we get from you guys not going so smooth if I proceed this way.

Lastly, when I create a custom document type, how do I give it a custom image to display whenever a user is creating a new document? Currently, the standard document types each have their own nice image (FAQ, Article, News, Page, etc..) but I cannot seem to find where you would set that for custom document types.