help please to run spamassassin _and_ ravantivirus from postfix

["Chris Evans" <chris1@psyctc.org>]

I have been happily using postfix's antispam for my fairly small 
volume Email list (opt in!) server for nearly a year and using 
ravantivirus for antiviral cover.  However, I'm getting more and more 
spam despite my rbl lookups 'cos I just don't have time to keep 
updating my postfix body and header checks.

I want to go over to using spamassassin and probably Vipul's razor to 
be more flexible but I want to retain ravantivirus and I want one 
system to cover all accounts and all lists on my server (i.e. not 
using spamassassin from procmail).

I think I can do:

mail in -> amavis -> spamassassin/razor -> ravantivirus using the 
right combination of 10025 and 10026 but I'm not a unix guru and this 
is beyond me to set up.  I'm sure I'm not the only one to be doing 
this so please can anyone give me fairly simple instructions about 
what to install and how to set up master.cf and main.cf to achieve 
what I want?

TIA,

C

P.S. Debian stable, I386, postfix 1.1.11, ravantivirus 8.4.2 and have 
the stable debs for spamassassin, razor and amavis.PSYCTC: 
Psychotherapy, Psychology, Psychiatry, Counselling
   and Therapeutic Communities; practice, research, 
   teaching and consultancy.
Chris Evans & Jo-anne Carlyle
http://psyctc.org/ Email: chris@psyctc.org