Both the internal IDE and external firewire drives are plenty fast enough for DV. I have a striped array on my Novell file server.
Yeah, 1.5 Gigabytes of RAM ... ya' know when your video card has more than six times the size of your first hard drive.
I have tried Linux Redhat a number of times and find it hard to get the drivers needed. I have a u.are.u finger print scanner, a CD-R burner, a DVD-R burner, a film scanner, color printer, dual monitors and just haven't found Linux drivers for them. I was able to get one monitor to work, get Sound Blaster Pro use out of my Live! card, and get the modem to work. So Windows 95 like.
I don't even want to talk about getting the firewire DV capture to work.
I run Novell, Solaris, Mac OS9 and OSX, and Win2000 at work. We were using Linux to run an IDS system (Snort) until we went ligit.