For meditation during the day I think something in the High Theta or low Alpha range would be good.

For before or during a WILD attempt I would suggest something in the mid Theta range.

Here is the place I got mine from Free Binaural Beats - FREE High Quality Binaural Beat Downloads!

There are beats there which are specifically for Lucid dreaming, meditation, Sleep, and so forth. You may need to check a few to find which works best for you.

I have read good things about isochronic tones as well. They seem to be very similar to binaural beats in effect, but slightly different in how they work.

"Isochronic tones are regular beats of a single tone that are used alongside monaural beats and binaural beats in the process called brainwave entrainment. At its simplest level, an isochronic tone is a tone that is being turned on and off rapidly."- https://en.wikipedia.org/wiki/Isochronic_tones

While Binaural beats use two tones.