First - you need to be aware that with a JBOD configuration, failure of either drive WILL result in ALL the data becoming inaccessible, even if that data is container entirely on the remaining drive - let's say you have 500GB of data, all stored on the first drive, and the second drive fails, you will lose access to that data even though it is still there, on the good drive.
Think twice before using JBOD - or for that matter RAID0.
Second for remote access either directly to the NAS or via a desktop - consider using a VPN of some sort - your router may have that capability. With a VPN, its as if you are attached directly to the network, albeit somewhat slower.