I have an easier solution, power line network extenders. As long as your power lines aren't too old, you should be able to get 100-200Mbps if you buy the 500Mbps+ options. That's assuming you don't go through the main switchboard or something similar. These are apparently quite good for the price and might even allow you to max out your connection -
https://www.smallnetbuilder.com/lan...it-passthrough-powerline-starter-kit-reviewed
It would seem that the QCA7500 based models are the best ones out there today in terms of performance.
Keep in mind that the upload speed is usually a lot better on something like this than using Wi-Fi.
It's that, or get a 5Gbps capable extender. It won't be as fast, but even at AC1300 you're going to hit at a minimum over 100Mbps.
Your pings are all over the place which is most likely down to the extender, as I have a stable 12-20ms ping on my wireless extenders, but that's normally slightly better than you should expect. That said, hitting over 200 at times is terrible, especially if you plan on playing games on your PC.