Hi Craig,
The best forum I know of that is dedicated to the Type 3 is located on TheSamba in the US.
http://www.thesamba.com/vw/forum/
There is also the ShopTalkForums, also in the US.
http://www.shoptalkforums.com/
Type 3 people from all over the world post there. I would add it to your list of favorites. Best of luck with your new car. You can build up an engine easily enough, but you will need to come up with the cooling tin and fan components, but they are available, it is just a question of where. The wrecking yards are also a good place. I think I saw a posting in the General Chit Chat area from a guy how found a yard with a whole bunch of 3's.
Dennis