With all the research that I did, I came to the same conclusion. I ended up purchasing a NetGear WN2500RP and went through the setup, getting frustrated with the fact that as soon as I unpacked it, it simply wouldn't connect (through the "setup wizard") to my existing WLAN. After about an hour of reading that there was no connection, I simply chose to "connect later" and then went through the rest of the wizard. ah heck me if, once completed, the 2500RP showed connection to my WLAN and all devices connected to it operated as advertised.
So, all in all, I completed what I had intended on doing although a few more grey hairs (on account of the initial setup of the NetGear device) have adorned my noggin. Since then, everything's been working flawlessly.
Additionally, I had used the electrical wiring / CAT5 extension system which worked "to a degree" : I never got better than an "orange" (medium) connection with it's paired partner, typically it was red - which did work, but wasn't all that consistent. I've read since that these Ethernet over Power systems typically work best when on the same electrical circuit in a building. My house is over 40 years old (which probably accounts for something as I'm sure the wiring isn't what it used to be) and for "general" house use, I had to span across three of the possible four circuits which all that I've read, explains to avoid. Laughable really, as if someone is going to rewire their electrical outlets to be on the same circuit so that Ethernet over Power works? I don't think so.