Option to synchronize contacts should be available in either the scriptable setup (ie: rep.contacts=1 in text file) or better yet, via a desktop policy.
Currently, on version 8.0.2 of Lotus Notes, it is enabled on a client by client basis. For some reason, some of the clients have it disabled (the option is not available) on the replicator page. In this case you have to enable it in the contacts preferences in names.nsf then enable it on the replicator page.
For this reason, a synchronize contacts desktop policy is preferred?
PS: If anyone has a creative solution for this or know if it's enabled in 8.5; don't be shy......share. ;)