Ready NAS 422 Folder Syncing from alternate drives

I am looking into purchasing a NAS box for my home (I already have the WD Red 4TB drives) and I am very interested in the Netgear Ready NAS 422 enclosure (I'm not sure if the model # I put above is correct or not); however, the more I have read about it, it seems as if the Ready cloud app will only let you sync to folders that are located on the C: drive of the PC. Can anyone verify if this is correct? If so, I may need to look elsewhere. I have numerous drives in my PC (such as D:, E:, H:)  and I am interested in syncing folders from these various  drives to my NAS. So, if I make changes to the files on my NAS, the files will be updated on my PC drives/folders and if I make changes to the files on my PC, they will update on the NAS (2 way sycning). I have been reading that the Ready Cloud app does not allow this and will only let you sync files that are on the C: drive. I have very large folders conatining my graphics files and store these files in 2 TB drives in my PC but I want to sync them to the NAS so I can access them from my laptop when I am somewhere else. That way if I change/edit graphic files on the NAS, they will update on the PC drive as well. I hope this is not the case since I would really like to purchase this NAS enclosure. Are there other apps you can use with this enclosure other than Ready Cloud that could accomplish this? If not, I will need to look at a Synology or something else that can handle this. Any info anyone can provide would be great! Thanks!