Mailserver, Anti Spam solution

We are running a relay Mail server on our LAN. It works fine, but the emails are getting caught in spam filters and being flagged off on Real time black list servers. We need anti-spam and security technologies both inside the firewall and outside, including firewall configuration. We would require the following configuration:

a. Postfix (for SMTP)
b. Dovecot (for IMAP) (NO POP3)
c. OpenLDAP (directory store)
d. Amavisd-new (interfaces between Postfix and antivirus and antispamtools)
e. SpamAssassin (anti-spam tool)
f. ClamAV (Anti-virus)
g. PostGrey (policy check)
h. DKIM (Domainkeys Security)
i. DNS / Bind (for ensuring no unathorized lookup happens) j. Barracuda Reputation Block List Service (For authenticating against spam databases) k. Anti spam gateway (To block spam mails) l. SPF (Sender Policy Framework)

m. SASL (authentication)
n. TLS (Encyption)
o. Fetchmail (For fetching mails from remote and sharing on local server)
p. Webmail (Roundcube)
q. Tarpitting

The above needs to be installed, configured and fine tuned so that we have a optimal solution. We need this to be done with knowledge transfer to our system administrator to enable regular maintenance locally.