which db type?

[Chris S <taskara@internode.on.net>]

Hi there,
Would people mind offering advice as to which database type I should use 
with openldap?
The machine will be a web, email, etc server. Dual Opteron 246 with 4gb 
ram, 3 x 300gb sata drives in hardware raid 5.

I am trying to get openldap to be the central authentication system for 
sftp and courier, hold aliases etc for postfix, as well as dns entries 
through bind, and if I can get mod_cfg_ldap to work then also vhosts for 
apache2.

Many thanks,
Chris