I also agree with niko's networking comments, I think you are maybe being told porkies.

There is a difference between home and business when it comes to networking, as in xp (It's a bit of a bugger to access shares on xp home from xp pro, but the other way around is OK) but fundamentally, networking works in home.

Also that drive setup (RAID 0+1) will give improved performance as well as redundancy. Remember however that RAID will not protect you from human error. If you accidentally delete a directory you may be screwed (If you realise straight away and undelete you would probs be fine, but if it took a while to realise what you had done the data would probably be lost), so tape or optical backup may be an idea too.