Automatically sync folder contents in the background
Have a look at the answers to this question: Auto sync local files to remote
many of those suggestions are also relevant to you.

Another approach, if all you are trying to do is get Spotlight to index the SAMBA share, is to try running the commands:

mdutil  /Volumes/x -i on
mdutil /Volumes/x -p on 

where x is the Volume name of the drive.

I have heard that this will enable Spotlight to index the network share.

More info and discussion here: 

http://forums.apple-group.com/archive/index.php?t-3679.html