RAID 1 is How I Roll

Backup Progress
Originally uploaded by dcdan.

Rsync isn't really cutting it for a backup type solution for me (one it takes two long and two I forget to do it often enough) So I'm backing up to my 200GB drive and building RAID 1 on my two 250GB. Does anyone have advice on how to work it? One 250GB is in USB 2.0 case and the other is in a 250GB USB 2.0/Firewire 400 case. The eMac that they will be hooked up to only has 2 USB ports. So any suggestions on my choices?
1) Do both on USB on a USB 2.0 hub (will this cause a performance issue?)
2) One USB, One Firewire?
3) Buy another Firewire case?
a) Link to both the Firewire ports on the eMac
b) Link to the Firewire ports from drive A to drive B?

These are some of the things that keep me awake at night.

Thanks