Safest route would probably be to find a board that supports both RAID 0, RAID 1, and RAID 0+1 for the future.
RAID 1 is when both drives act as one both mirror each other ie: the same file is saved to both drives just in case one fails. But that means that instead of 240gigs you have 120gig, I also think that it might be slower too. RAID 0+1 has features of both without some of the drawbacks, I don't know too much about RAID 0+1 so maybe some one else could fill in the holes?
But it just means that your going to have to take a pro-active response to backups. As for getting a Zip, I say forget it and get a DVD+/-RW instead. Many good ones can be had for around $99-150 USD mark, although the $99 ones tend to come with lowend burning software while the $150 area ones come with a full copy of Nero or similar program.
Yeah, or you could just get a program like norton ghost and ghost your drive every once and awhile, much easier than backing up to zips or other form of storage.