I recently had a meltdown on a hard drive containing files that mattered.  I have a small home network of 3 PCs - one of which is a server (running Win 8)used as the destination of backups from the other 2 PCs (running Win 7).  The server got moved a few months ago into a bedroom and subsequently gets turned of on a nightly basis.  I was using a combination of event-based[1] backup to the server (using memeo - www.memeo.com) and scheduled backups using syncbackfree to skydrive.  The scheduled backups all ran monthly (because of data cap considerations).  My wife and I run two small businesses so data availability is a key driver of our financial health and ther meltdown occurred on one of the non-server PCs.  When I came to restore files from the server PC using Memeo many files were missing significant data and therefore the files had not been backed up recently prior to the meltdown.  I can never know the root cause of this because the evidence is on the failed disk.  As a side issue the drive was sent to Computer Forensics Ltd and although they were able to fit replacement read/write heads said heads came into contact with the platters during calibration when the drive was powered up so that ended all data recovery hopes.

So now I am looking at having an external, always-on backup destination that is independent of all 3 PCs.  I also have an Orcon Genius with a storage USB port so I am considering an external drive hooked up to this port.  If I do this then all things being equal the backup destination will be as available as the Genius is.

Looking around at available hardware the choice is overwhelming.  For external drives Ascent lists 110 products from 16 brands.  Which one to choose?

I am wondering whether RAID 1 (as a minimum) would deliver any significant hardware resilience over non-RAID drives?

I am also interested in Western Digital drives because they include backup software that can do both scheduled and event-based file backup.  Are there any other similar hardware/software packages I should consider?

I would be grateful to receive any recommendations on both hardware and software.

[1} I define event-based backup as having a file backed up whenever it is saved or changed in any way.