Actually, Amazing Charts V4 has SQL Server Express built in, and won't just tie to SQL at this time. Thus, I would install V4 and see how it goes.
Simply doing this on a peer to peer with or without sbs2003 as the main operating system has made a tremendous difference in speed.
I recommend using xp or vista as the main computer operating system, by the way, as sbs2003 opens a whole other can of worms given how complex and confusing it is to set up and use. If you have sbs2003, you pretty much will need your own IT person to manage the network and computers.
