[Serusers] Question regarding SER/Asterisk functionality

Hi all, I'm currently looking for a VoIP platform to support the following features: Caller ID Call Waiting with caller ID Call Hold/Retrieve Three-way conference Calling Line Identity Presentation Call back last missed call Last called number redial User line locking/Call Barring (all current levels) Itemised bill Call Forward Call Forward on No Reply Call Forward on Busy Call Forward Unconditional VoiceMail - Message Waiting Indicator - Call back option Number Portability Secret Number Legal intercept Emergency Number Routing Anonymous Caller Rejection Directory Service update Feature code activation I have looked into both SER and Asterisk, and found out that SER should be the most appropriate platform since most of the users will use a SIP adapter/endpoint and be located on the Internet (like most of the VoIP services these days). So my question to the list is to gather some experiences and possible remarks/comments on which direction I should go :D Any help would be gladly appreciated :-) -- Geir