RAID arrays with 3 or more disks (e.g. 2 data and 1 parity) are for when the data won't fit on one disk. A simpler strategy is to just mirror disks. So you'd have a pair of (say) 36 GB disks. 8 GB of data is chickenfeed these days. Note that the 2+1 scheme won't keep running through two disks failing either.
Really, this is quite a small site (what's the maximum number of visits there's ever been in a single day?) and putting it on a shared hosting service should be fine. Those services all use RAID, do regular backups, and all that sort of thing.