From my limit knowledge, I think your are going to loose your wireless capabilities, since Network Space doesn't have a wireless network interface. In this way, I think you may have to compile an appropriate driver for Wireless Space and after that modify features and options on base software to support it.
However, for Network Space, maybe you can try an alternative firmware from here: http://plugout.net/viewtopic.php?f=3&t=802
I have check with them if it's possible to have their firmware running on Wireless Space, and since they are different pieces of hardware it's currently not possible.
BTW, you just told you are using a 4TB external HD via USB on Wireless Space. If that´s true, do you mind sharing how this HD is connected to Wireless Space and how did you made it to happen (filesystem type, partitions, USB port in use, etc)? I have a Seagate 3TB external USB HD and I'm not able to use it at all with Wireless Space.