Just to say, I have the same powerline adapters you said you currently have, and I installed the same Gigabit switch mentioned above last night (the 8-port version of it at least)...
According to the lights on the switch (which the manual says light orange for fast-ethernet devices and green for gigabit) the powerline adapters are connected at full speed, which I was surprised by... I haven't had a chance to test the speeds over the adapters though so perhaps it's not but even still for my other devices the switch is fantastic
One thing that's worth considering is whether there is any way to get your router closer to your desktop/NAS room. I was in a very similar setup to you and I had a plan at one point to use powerlines or maybe run an ethernet cable from my router downstairs to my office room upstairs... but then I realised that the very small ADSL cable would be much easier to run upstairs instead, so now I have:
- Telephone socket downstairs, connected to ADSL microfilter and telephone
- ADSL cable runs up the stairs (used some very thin PVC trunking) and passes under the inside edge of the door to my office room
- Router in the office room, connected to an 8-port switch
- Switch connected to my Desktop PC, my server, NAS and a powerline adapter
- The other end of the powerline adapter is back downstairs in the living room connected to a raspberry pi under my TV
Anyway just an idea - Good luck!
