Don't waste your money on a rental. The humidity will return within a few hours once you return it. My basement is the same size as yours but it's finished. I bought this dehumidifier on Amazon about 2 months ago and it has been a blessing.
Before the dehumidifier, my hydrometer measured 80 degrees relative humidity. It has since dropped to a steady 50 degrees relative humidity for the last two months. There's a 2-gallon bucket that needs to be emptied every few hours but I have it hooked up to a condensate pump to keep it running 24/7.
I have a tosot that I’m happy with. It’s a 50 pint that I use “outside” of my 4x4’s that in turn changes the humidity in my tents. It covers the whole room pretty well and quickly. Relatively inexpensive and supposedly covers a 4,500 Sq Ft area.
Auto turns off when it hits the desired setting/range (settings you can make in increments of 5 degrees. It will also turn off if it’s tipped over or the res is full.. I probably empty once every few days, but you can add a hose and drain all day for continuous use.