I'm not following what you're trying to do here.
Have you upgraded SP to 2007 or are you still running 2003?
Now.. What do you want to sync? Just email data? Contacts? If thats the case, do you really want to sync it from Sharepoint? You'd probably have better luck just using the DM on a machine w/ Outlook on it since I've never heard of someone trying to sync a BB (or any other device for that matter) with SP.
I've never worked with MS SBS, but if my understanding is correct, Exchange 2003 is part of it, and this is the 'source' of your email. If that is the case, all you are doing with Sharepoint is linking to exchange and showing the contents of your mailbox. Same concept as using outlook to view your mail.
BB devices I've owned: 957 : 7750 : 7250 : 8703e : 8830 : 9530 : 9630 : 9650 : 9930 : 64GB PB
BES 5.0.4 ~ BES 10.1