Okay guys, i have made some progress!
A friend of mine, a teacher, was wonderful in such that she helped me heaps with this. I went with the suggestion of writing a letter / proposition plan for my acceleration. Essentially it boils down to this:
I will be siting on all the HSC mathematics classes. Unfortunately, Preliminary Mathematics extension 1 clashes with HSC Mathematics. So i have decided that i will do Preliminary Mathematics Extension 1 through Distance Education while doing the HSC advanced mathematics course at school. When i finnish the HSC mathematics ie end of term 3, i will go back into my Mathematics Extension 1 class to continue into the next year as well as start Mathematics extension 2.
Now this has not be confirmed yet, but it seams very easy to get to work. Also, alot of the teachers at school that my teacher friend saw thought that it would work and is good for me.
I will tell yous how it goes when i know