Circle Packing on a Surface with Set Diameter

Hello Grasshopper community!

The image below, demonstrates Grasshopper's ability to circle pack on a surface.
I am making this post to see how I can specify the diameters of the circles.

Is there anyway to restrict the diameters of the circles that are being packed into this surface before running the Kangaroo simulation?

Say for instance that the circles packed on the surface above are only circles of the following specific diameters; 1/2", 1", 1 1/2", 2" 2 1/2". At the moments the circles live within a range of diameters, I am looking to specify those to 3 or 4 set diameters.

Thank you so much for the help, let me know if you need any other clarification!

Please find the files attached below.

Some related posts:

http://www.grasshopper3d.com/forum/topics/packing-circles-on-surface

http://www.grasshopper3d.com/photo/circle-packing-1

http://www.grasshopper3d.com/forum/topics/circle-packing-similar-to...

http://www.grasshopper3d.com/forum/topics/packing-circles-on-curved