You can indeed only select Wireless Router mode and shall in your situation disable the radios.The interface of both routers will show each other in the client list.
The setup seems correct to me.
You shall focus on the wireless side, a few hints:
Set 2.4 GHz to a Channel bandwidth of 20 MHz.
Set a different SSID for 2.4 GHz and 5 GHz, e.g. "myhome" and "myhome5", this makes it easier to connect a client device to the right frequency band.
Use alphanumeric characters only for the SSID's (Aa to Zz and 0 to 9, no spaces and no odd characters).
Use InSSIDer or a similar program to determine the usage of wireless channels in your neighborhood, do the check at various locations in your house. Do this check at least every month (new neighbor devices may have arrived or neighbors may have changed their settings).
Set 2.4 GHz to the least used channel out of 1, 6 or 11.
Leave 5 GHz to Auto channel (if possible exclude DFS channels) or set it to the least used channel out of 36, 40, 44 or 48 (the non DFS channels).
The range of 5 GHz is practical about half of 2.4 GHz.
Relative position of the router to the client devices is important, a free line of sight is ideal.
Keep as much as free space around the router as possible, do NOT place the router in a cabinet, do not place it on top of another electronic device.
Keep the router on distance from your modem, your TV, wireless telephones, microwaves and bluetooth devices.
Keep the router on distance from materials that absorb or disturb radio signals e.g. metal objects, concrete walls or floors and waterfilled objects.
Keep an eye on router temperature, place the router on a hard surface to allow natural ventilation through the router box.
Experiment with the location of the router and antenna orientation.
After a major firmware upgrade (or when recommended in the release notes): do a hard reset of the router and manual configure the router again (do NOT load an old configuration backup file).
In case of doubts, forgotten settings and weird issues: do a hard reset of the router and manual configure the router again.
Write down the setting changes you make from the defaults.