Forum with registration features

[amicodiponji]

Hi! I am a WordPress newbie.

I’d like to add a forum section inside my blog, a forum with registration system, where registered users discusses their ideas.
I tryed some plugin (bbPress, WP forum and other) but when I logout from admin user and I try to register as an external users, I am reditected to Worpress login page.
I don’t like this as my users should not notice that I am using worpress.

Can you please suggest me a forum plugin with registration features (email confirmation, lost password etc..)?
Or can you provide me a link with a tutorial to customize bbPress or WP Forum Server?

Thanks a lot
Stefano