DreamHost offers an one-click install of phpBB but you could always purchase and install vBulletin on your own.
I'm in the same situation, my ISP is Earthlink/Covad and they also block port 25 for SMTP. DreamHost offers an alternitive port for SMTP, port 587.
If you just want to redirect then you can redirect unlimited domains and it won't count against your allowed domains.
If you set it to mirror the domain, e-mail, subdomains (you have to set those up manually but I do for one of my domains) but that's why DreamHost's basic plan includes 3 full domains.