Dark Matter
This is very sloppy... E-mail me if it does not make any sense! I'll be happy to talk to you and improve it!

In both estimates I see the dark matter halo as formed of infinilety thin equally spaced concentric spherical shells. Theese shells move back and forth, casuing the clocks to slow down and speed up. The purpose of these calculations is to give an order of magnitude estimate of this difference.
 

 Newtonian Estimate:      0.3861279126*10^-15
 

Relativistic Estimate:    0.3575165008*10^-15

Kip's    estimate
For epsilon = 1, Kip's estimate agrees with mine. I think we could gain an extra factor of 10 from the density and a factor of 100 from the wavelength. Than it would be very easy to see the waves. For the above numerical values, it would be possible, but hard to see them.