Lots of open-source tools can do the quarantine thing for you.. MailScanner does great quarantines for example. You just need a cron-job to go through and clear out your quarantine every once in a while. (It stores them under date-named directories)
Quarantining is not a problem, since procmail could do that job; I'm looking more into the posibility in that spam report thing with the option to deliever that email. Anybody? ;-)
