Uh oh: No Snow Leopard on crazy Mac Pro config

I tried to upgrade my Mac Pro today to Mac OS 10.6 (Snow Leopard), but I didn't get very far:

Hrm. That isn't going to work.

I have a crazy-ass 6 terabyte setup in my Mac Pro, and the Snow Leopard installer definitely doesn't like it.

I'm amazed that this worked to begin with!

Although I've been really happy with the current confirmation, it may be time to make some changes. I only have 80GB left on my 2.5TB data partition! I'm thinking of simplifying the setup to something like this:

Drive 1 (boot): Intel X25-M SSD for Mac OS X boot and apps Drives 2+3 (data): 4TB volume -- 2 x 2TB RAID 0 (stripe) Drives 4+5 (live backup): 4TB volume -- 2 x 2TB RAID 0 (stripe) Drive 6 (scratch): 300GB WD Velociraptor

Can anyone suggest improvements? ;)