With any digital chip, like with Arduino, you must not connect a data signal to any pin which is a higher voltage than the chip's Vcc pin, otherwise the chip can be damaged.
In your circuit, the IC will be powered by, let's assume, 4.5V. So your voltage divider must reduce the 5.9V signal to 4.5V for the IC's input pin.
The 6 inverter gates in the chip are identical. Connect the voltage divider output to the input of whichever gate you choose.
No. You need any 74hc00- series chip containing simple, inverting, logic gates. The 74hc04 you found on Amazon, for example.
Another example is 74hc00, which is quad nand gates. A "nand" gate is an and gate with an inverted output. Connect one of its inputs to Vcc and you can use it as an inverter.