@cp2000 JBOD is something that can be done through your motherboard BIOS (on most mid- to high-end ones) and most multi-disk storage enclosures also have it built-in. However doing it that way also has drawbacks, because it is done on a "hardware" level, below the filesystem. Your storage controller (whether it's the one in your motherboard or in the enclosure) doesn't have any notion of files. It just sees storage devices as having a bunch of 0's and 1's on them without any understanding of what the data means. This prevents it from providing some of the more advanced functionality you might want in your storage solution (file sync / duplication etc) and also means that a single file could potentially be split across more than 1 disk.
What you most likely want is a more high-level software solution. Personally I'm a Linux guy so my experience with Windows solutions is somewhat limited but as far as I know StableBit DrivePool is hands down the best option in that category. It is unfortunately not free (one-time $30 purchase) but then again, since you are on a torrent site you might not be averse to some piracy. I would highly recommend checking it out. You will probably find it's exactly what you're looking for.