What kind of cooler should I get if I plan on storing both red and white wines in the same fridge?

I also had the same indecision and finally I've purchased a dual zone wine cooler. The dual zone wine cooler allowed me to maintain two distinct and separated temperature zones within the same cooler which was exactly what is was looking for, and I think this is the optimal solution for you as well.

White wine should be stored in the temperature range of 46-56 Fahrenheit depends on the kind of white wine you store (the recommended temperature should be written on the label).

Aside from temperature, humidity is a major concern. The low humidity levels can cause the cork to dry/shrink allowing room for both air and other food odors to enter the bottle and tamper with the quality of the wine inside. Wine coolers offer an optimal humidity level of 50-80% needed to keep your wine in good condition.

Red wine should be stored between 58-68 degrees Fahrenheit and the whites should be cooled at 46-56 degrees.

A single zone wine cooler allows you to store only red/white wine correctly. The cooler has only one temperature control and one space for storing your wines.

http://www.haieramerica.com/en/asset/archived/BC112G.pdf
is the link to your manual.Typically in a dual temperature zone wine cooler whites are stored in the bottom and reds on top as whites are better a little colder and the cold air will drop to the bottom of the unit.
Hope this helps!

It's between 55 and 65 degrees fahrenheit. If you're storing a lighter red wine, you'd want to keep it on the lower end (55 degrees). And for the darker (deep) red, you'd want to keep it on the higher end (65 degrees). All white wines should be on the lower end, and below. You can drop down to 50 degrees if you'd like. I hope this helps. Good Luck! 

If you just want to use the factory settings then push the red or white button depending on what you store the most.
Or you can set it yourself by pushing the red and white buttons together for about 3 seconds- the temp display will start flashing-then use the red and white buttons to set the desired temp-then push the set button

All the wine chiller set 2 temp red and white, red wine temp only for 18- 20 oC , your using white wine don't set red wine temp , set only for white temp mode,white and red wine set temp are different temp

Push the red and white buttons at the same time for about 3 seconds-the temp will start to flash-then press the white button to lower the set temp-when you have it where you want it then push the set buttom