Ability to use RAID, current setup only has the capacity for 1 drive.
Is this a good option or is there a better option?
I've also been considering using an external drive enclosure with software RAID, but I heard that could be unreliable.
EDIT: Is the price good? Shipping is quite expensive (about $100), so I'm only planning on buying it if the deal is good.
If RAID is what you're after, don't mind the premium for SSD storage and have available 5.25" bays, I highly recommend 5.25" mobile racks. The one I'm using is a a cheap 4 drive one, but if you want something more premium there is always ICY DOCK.
i got a Fujitsu D556/2 (SFF as well) exactly because it seemed to have an optical drive bay. Turned out it does not have one, but some double sided tape and ugly cable management solved the issue for me :D.
My model, and I believe all other, have a 4pin molex connector for the power and as many sata ports as the rack can handle (in my case 4). My "mobile rack" came with 4 rather long sata cables (about 30cm) so it was easy to fit them through an empty pcie bracket slot and I just had to buy a somewhat long 4pin molex adapter.
The drives are practically internal, they are just located outside of the case in said "mobile rack".