I have a small holding as well. Insofar as I can ascertain, and having read the SPP offer documents, there seems little to suggest that some holders will be favoured over other holders. I could be wrong but I haven't read anything that supports the view that some will do better in the SPP than another holder.
I will subscribe for 30,000 more shares as well.
I have held since 25 August 2008. Maybe, I might get some favour for the length of the holding?