mindwaves,
I provide hosting services myself and have done all of that stuff with the musicians I work with, so PM me if you'd like to continue this conversation further.
To get you started, the wiki used by the Wikipedia is called "Mediawiki". It is open source, and is the most simple and straight forward of all of the wikis I have used. There is a good chance that your contributers will have some familiarity with MW. I've setup a few MW driven pages on my own site which you can see
here.
As far as forums go, the new version of phpBB (version 3) is excellent, and open source. My goofy, famous, and ever so popular
Fuzzy Wombat is based on phpBB.
As far as domain names, I would suggest registering yours as soon as possible. Your domain is your property. You can have any webhost host your domain (including me), and relocate your domain to another host as you see fit - you have complete control over your domain, this is your legal property.
Again, if you'd like to discuss this further with me, I await your PM
