ICE particle avoidance and instanced geometry scaling

[Anonymous]

I have an ICE simulation with two big challenges.
1) I want the particles to avoid each other and not overlap
2) I want to randomize just the x and y scale of the instance geometry (again without overlapping with other particles).

The simulation uses instanced geometry that flows along a curve. My emitter is a simple rectangle that matches my desired width of the simulation.
The instance geometry is also simple rectangles, all of the instance particles flow on the curve at the same orientation and pace.

ICE is pretty challenging for me, so any information on how to figure this out is greatly appreciated.

I'm working with Softimage 2010

Thanks,
-B