The typical scree given in gardening books for growning alpines is about 9" deep and about 75% fine gravel or grit with the rest being soil/peat.
Id assume that the stone used would have to be pretty fine, and you might need a layer of coarser stones underneath it to serve as drainage.
Sounds like a lot of work to me, and pretty costly. From what ive heard plants that will thrive in scree will be quite happy in the cracks and small crevices of a rock garden provided the soil mix is right.

Thanks for the reply Taiga0. I think I will try with the cracks and small crevices of the rocks around the area instead and see how that does before trying to create my own scree :)

Much appreciated,
Ross Wexler

Scree just refers to loose rock that is not anchored in matrix. Many alpine plants on slopes have roots that just 'go with the flow' if a bit of the rock around them slides. This includes plants such as phacelia, physaria, many erigerons, crypto ferns and so on. These plants are the easiest to transplant as they are often displaced through slides, can have exposed roots and then re-root. Some sedums do better if the roots are exposed for a few days before transplanting as this is what they have evolved to do in their natural environments.