SATA RAID Configuration

[LKAlbert]

I have an ASUS A8N SLI Deluxe motherboard.
It has the capability of connecting 4 SATA drives via the Southbridge chipset and connecting 4 SATA drives via the Silicon Image controller.

I have two 74Gb Raptor drives that I want to configure as Raid 0 and I have two 34 GB Raptor drives that I also want to configure as Raid 0.

I have two Plextor SATA double layer DVD drives that I want to hook up, not as Raid of course.

Questions:
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(1) Which drive should be the boot drive, the 34GB or the 75GB?
(2) To which controller should the boot drive be connected?
(3) To which controller should the other Raid disks be connected?
(4) To which controller or controllers should the two DVD drives be connected?

I have gotten many different opinions. Among them are:
(1) Southbridge is fastest SATA connection so configure both Raid Arrays on the Southbridge, some say only the boot drive
(2) Use the 74GB drive for the boot drive because it is the faster
(3) Have the two DVD on the Silicon Image controller
(4) It does not matter what you do, they all will produce the same results
(5) Split the DVD drives between the two SATA controllers to speed communication between the two.

Does anyone have more precise knowledge?
Your help would be appreciated!