External Hard Drive Options

I am running FCP 5 on a MacBook Pro. For the last year I have been using LaCie drives and capturing 8-bit uncompressed SD video. I have run into some drive failure issues. I want a new system, possibly a RAID 1 mirrored drive. I want the low cost options like CalDigit and Wiebetech. I use the Firewire 400 port for the AJA video card. What are the best options for this configuration?

I've had no trouble with LaCie 500GB firewire 800 drives using 8-bit uncompressed video. The issue is back-up. Will it work when I'm using a dual firewire 800 and the firewire 400 (video card) or do wiebetech and caldigit offer the small mirrored drives with the SATA connection? Has anyone had experience with that?