RAID Questions

Hope I can make this clear enough. I have a dedicated server running SBS 2003 with two hdds with RAID 0 for 10 computers (XP Pro) use is digital xrays and other sm. dental software. I now know R O was dumb - no fault tolerance, correct? I want to switch to a mirrored RAID - don't need the extra speed of R 0.
I'm thinking, I should back up the entire sys with Win. Server Acronis to an ext. hdd, restore the back up to one disk.
But, I don't know how to change to the mirrored config.- not sure it's worth the time or risk to DIY - Should I take it to "my local Guy"?
Thanks for your time M.Geeks