Sorry but it sounds like the easiest and best OS for what you want to do is XP.
Its very much like Amiga after all. Applications multitask and you can fire up a prompt just like Cli in Workbench. Better yet every web page you will want to view will look great because you can run Internet Explorer which is the de facto standard for web pages if you look at browser standards. And you can easily connect your digital camera to the USB port and transfer pictures. Windows is not that bad really. For me the choice is easy, I work as a web designer and I dont want to pay to be in the exclusive Apple club.
An XP machine feels like a good old Amiga on stereoids.
