Hi Bret,
I’m new to macs too, but I can share a bit of what I’ve learned. I read that you don’t need ecc ram, its overkill – I have non and it is just fine. Crucial seems to be the overwhelming favorite brand.
As for fw drives, 400 will work as good as 800 for dv. I build my own with bytecc enclosures from newegg and seagate drives (had bad luck with western digital). For HD it seems that people are using SATA drives now. There are lots of external arrays and cards, just search the list. One I’m thinking about is promax’s Satamax array. Good company, good support.
Best of luck, I’ll be watching this thread to learn some myself too.
Stu