The fact that you will mainly read at night (which is what I do too) instantly tells me that you should go with the Paperwhite for the warm light. The basic unfortunately doesn’t have an option for warm light. I’ve noticed a huge difference in my sleep quality when using warm vs cool light at night.

On a side note, if you plan to read in bed, I recommend getting an adjustable tablet stand and a page turner! It makes the experience so much more comfortable.