Gateway or Non-Verizon Router Recommendation with a catch

[Gettes1]

I could not find this exact situation in any of the many threads I've reviewed on the topic. 

I just switched to internet only 75/75 service. Currently I have the Actiontec router hooked up in my second floor office via coax. The desktop is connected via ethernet to the router. I also have an extender hooked up in the basement directly to the ONT. 

Since I am now relying on streaming for all my family's TV watching I am looking to upgrade/improve the Wifi performance if possible. Currently the signal is pretty good and I've clocked speed from 30 to 70(over Wifi). We do get an occasional buffer when using some streaming services. 

I do not have ethernet run to the second floor office and I would like to keep an ethernet connection for the desktop. My plan was to purchase a Gateway, connect it to the ONT via ethernet in the basement(which is also just below our living room where most TV watching takes place) and then move the extender to the second floor office allowing me to retain an ethernet connection to the desktop. Seems to be the easiest least hassle way to upgrade.

I would really like to be able to use a higher quality router but am somewhat worried about not having the ethernet connection in the second floor office. Office computer is used for some gaming. Looking for recommendations as to the best setup with this particular scenario. Thank you in advance. 

[Edg1]

What you saying would definitely be the easiest way. If you wanted to use a higher end router you could get a pair of MoCA adapters to wire your office. 

The setup would be the ONT via ethernet WAN. Connect LAN to first MoCA adapter and the home coax to the adapter. Then in your office the coax to second MoCA adapter then ethernet to your computer.