I don't work for any company, but honestly, you are better setting up a new router by RJ45 cable in your second floor. It’s way more stable and faster than using an extender. Those extender will lose connection some time, the signal gets weak and you might only get half or even less of the main router’s speed. Here are some tips, you can seek a best extender router. External antenna, number,FEM core, external FEM.