Forum plugin?

[expozitum]

Hi. I want to integrate a forum in my WP site. Mos important is that it would be one register/login for both WP site and its forum. For instance if a person registeres on my main site with username “big joe” he could immediately post not only comments on my main site, but also on the forum. Or vica versa – if person registered on the forum he could immediately post on my main site as well.

Is there only that single WP forum plugin or could I use mingle forum or zingiri forum in such a manner? Like I said one time register/login for both site and forum is needed..

ps: also I would like to skin the forum with the colors of my main site, is that easily done?

Thanks

[webjunk]

Have you tried looking yourself? bbpress among others

[expozitum]

tried, looking for some genuine feedback from people here