vexim + SA + DSPAM

I have a shiny new installation of vexim.  Works like a charm.  Now I'm 
trying to get similar functionality as with my 'real' accounts.  I 
handle spam in the following way:

After the usual checks, mail passes through SA.  SA simply tags it as 
spam in the headers; it doesn't modify the subject or anything else.

The message is then passed through dspam.  Dspam examines the headers as 
well.  It uses the SA results and tags the message as [SPAM] in the 
subject along with adding its own results in the headers.

Lastly, exim, through the .forward filter, sorts the mail into the Junk 
folder.

It sounds complicated but it works; and it accurately handles perhaps 
99.7% of spam, with only one false positive in the last 6 months.

I found this ( you have to scroll down to the vexim/dspam discusison) 
but the vexim archives seem to be down:

http://www.exim-users.org/forums/showthread.php?t=52356

How do I go about setting up a system like I have with vexim?

--Yan