Use a list of objects as arguments for organic stone

Im starting from the beginning...so I want to make 30 or 40 geometric elements (ie the bumps that will be used in my travertine post) that will represent some of the extremes of the different types of shapes in organic stone pitting. 

The idea I had was to use a random spray of points over a rectangular area (along with some human intervention), then use these points as anchors. An object in the above list would be selected, attached to the anchor and transformed ie scaled rotated etc with various constraints and then the iteration would continue.

1. Generate random points on selected rectangular area (optionally be able to use some curves to generate a secondary 'vein' of points for strate)
2. Getting a list of objects from existing created objects
3. Iterating through the random points
4. Using random seed to select an object from list
5. Transforming the geometry, rotating, scaling separately on different axes, mirroring, skewing, perhaps keeping a current track value to scale using a fractal relationship
6. Continue iteration

Any help greatly appreciated

Cheers

Mark