For a gaming Pc a wireless conections (or PLC ones) aren't the best, if you haven't any wiring option the performance will depend on several factors:
- Distance from the Pc to the wireless router and number of walls in the middle
- Wifi signal saturation in your home from nearby wifi hotspots
- For PLC, the quality of eletrical wiring on the home, distance, number of elements in the middle of the two PLCs, etc...
First of all would check the wifi signal from the router in the point you want to put the Pc and if you have several wifis in the place that overlap to check if wifi would be a good option (for example with a Wifi Analyzer App on any android device).
Then if wifi would be ok, use a good router like an Asus Dark Knight or similar with QoS (Quality of Service) options with a good Wifi Adapter (not needed to be PCIe, you could find serveral good USB ones)
I would not recomend PLC on default because depends a lot on factors with very dificult checking, like the building quality of the electrical wiring ofn the home, interferences for electrical equipment, etc... i could work very well but it's also probably to work in reduced performance or even don't work at all, wifi is somewhat more predictable.