Undulating surface based on irregular points or Spatial Deform

First of all, this is my first post and I feel the need to say that, while I am still a grasshopper rookie, I've learned everything I know from this amazing forum, thanks!

Okay, down to business.  The reason I'm posting is that I'm having trouble generating a wavy/undulating surface.  What I want is to have the surface smoothly undulate, think sand dunes, with the high spots being defined by a random set of points/vectors (not based on a grid).

I've posted a definition showing what I have so far, essentially a set of random(ish) points on a surface.  From there I've generated the deformation vectors (also random) to use in either of the possible solutions I've thought of.  The problem is that neither of the solutions I've thought of seem to work for this problem.

Possible Solution A: I thought that the Spatial Deform command would be the best for this problem but the resulting deformations are very local and sharp, I'd prefer if they covered a lager area/made a smoother undulating surface.  I have a feeling that the falloff string in the custom spatial deform command might help here, but I wasn't able to make any significant progress there.  So how can I change what I'm doing with this command to create a smoother overall undulating surface? Or if I can't:

Possible Solution B: The other simple seeming solution is to use the Surface From Points command on the translated points (along with four corner points to maintain the original surface boarders).  However this only (seems) to work with points derived from a rectilinear or uv grid.  Because my points are entirely random there seems to be no right U value to input (i tried a bunch...) How can I make this work?

Sorry for the long post but this problem has been defeating me all day.  Odds are this is a simple problem for you Grasshopper masters and I'd really appreciate help on creating the surface I have in mind, either by troubleshooting the above solutions or by some other clever definition that will blow my mind...

Thanks in advance for the help, I'm in desperate need!