Well, I'm new here too but I'm about to take possession of my A1200. I found it on this website that someone posted a few days ago. I've also bought some items from AmigaKit online. They seem to post here often and they have a great website.
Ebay is also a good site but as always Buyer Beware or just be careful. Softhut is one site also.
I've gotten a LOT of very useful information from this website and the community here has been awesome!