From further research it seems I will not be able to build the latest drivers for Rasplex on the pi itself.
Could I please get an indication if the DLink DWA-131 (specifically : ID 2001:3319 D-Link Corp.), will be supported in the future?
From a little research on the Internet it appears that the are a number of problems with this adapter and raspberry pi's and it is not supported on OpenELEC, suggest you get one that is supported, search this sub forum to ascertain which ones are.