Re: HTTP_AUTH plugin/how to ?
“As well, if you have an integration with WordPress, bbPress integrates logins perfectly with WordPress.”
That said, if they are in different subdomains you will have to tweak some files (currently, anyway). But it’s two lines that need changing in total, and it’s very simple. 
If you’re planning to install WordPress, look for a WP plugin that does whatever you want and logs you in – there are way way more WP plugins than bbPress plugins.
