One thing I would advise on that is growing in talk in my IT community is the reducing validity of RAID setups. For years Raid 5 has been the darling of NAS/Server installs for space versus redundancy. However lately with a lot of these huge mega size drives becoming popular the issue or URE is rearing its head (unrecoverable read errors). These are only being found out after a drive failure and during the rebuild process. This can mean a 3 disk Raid 5 solution is pretty pointless and even 5 disk solutions can be rendered unreliable during the crunch. Due to the price of these large disks and low costs of these cheap Raid 5 NAS devices they are popular among low costs home users who potentially don't have great backup strategies.
In short avoid Raid 5 and only consider a solution that offers Raid 6 support and absolutely nail your backups idealy to a cloud solution.
The main point to take from your post is the lack of home user's backup solutions.
I wouldn't ditch RAID 5 just yet though provided you have a decent backup. RAID 6 will be comparable on read but takes a hit on write as it writes 2 parity instead of 1 parity in RAID 5.
Budget is also a consideration for the OP, having 2 parity disks may be a little too far, it would be cheaper to have a cloud backup such as Hubic.
In the OP's case I would advise, as I believe other's have already, to get a NAS box, Qnap/Synology and a Cloud based storage subscription, Amazon/Hubic etc.
As others have already mentioned how their setup is, incorporating the HP Microserver, I'll chip in with mine. I'm tempetd to get another one as the offer is on again!
All data stored on a Qnap NAS.
PC with 'work in progress', copied from the NAS, worked on then edited files copied back (it's all ethernet but I'm not the most patient, plus 2 other people could be accessing the NAS at the same time).
HP Microserver running ESXi virtualization which among other things has a Lubuntu (Linux) installation with scripts backing up the NAS via crontab and rsync - all automatic once setup. The Lubuntu data (the NAS backup) is then backed up to the cloud (Hubic) weekly.
A monitor/keyboard is required for the initial ESXi install but the microserver is then 'headless' for all other functions - accessed via vmsphere client running on your PC.
Although this may sound complicated, especially to those used to only Windows, it's not that difficult to configure. Linux has got a lot more user friendly
The Hubic service, among other similar, has an added advantage of allowing access to your data from anywhere with internet access, even using your phone.