(but I'd guess you might have already).
WRT imaging to DVD, Acronis will break backups into chunks ready for burning, and Acronis Support have promised direct burning in the current version. I have used Norton Ghost before and PowerQuest Drive Image (these have been combined now and are called Ghost AIUI) which both burn direct and to be honest I don't think it is worth the hassle.
If you have enough disc space to set up a partition (don't let Acronis configure it's secure storage!!!) to store your backups temporarily then producing DVD size chunks is ideal. You can create the full backup (overnight - if your system is like mine the first backup takes a while) and then sit at the computer to burn your DVDs. The disadvantage of direct burn is that you have to keep coming back to the computer to feed it DVDs - and if you verify the image Ghost/DriveImage doesn't do this in a terribly logical way which means lots of disc swapping.
I really recommend having enough hard disc storage to store your backups - especially if you have large amounts of material to backup. By all means burn to DVD but if you want to recover a single file (or even a partition) nothing beats having it on hard disc!! USB/FireWire hard discs are a possibility, but make sure your system can find them in DOS mode!
To answer your question - Imaging copies the whol partition, that includes System Restore data. Personally I always do a disc clean up and defrag before a full backup, including getting rid of lots of system restore points.
With hard disc backups and incremental backup capability you could actually disable System Restore as a quick incremental backup is much more effective than SR.
By the way you can still defrag your system, but it will make the next incremental backup a bit bigger. Using Perfect Disc as your defrag program has the advantage thatit minimizes the repositioning of un modified files so incremental backup sizes will be smaller (and quicker) than with some defrag programs.