Lowering my Mazda

I am getting ready to lower my mazda. I am wanting to lower it 5"inches (lowest I can go with current tires) I know I am going to need blocks in the rear. From what I have read 3" work the best due to the angle. How many leafs and wich ones am I going to have to remove to lower it the other 2 inches? And the front I know i need to flip my lower ball joints and that should give me an inch. Should I just crank my torsions down or will they need to be rekeyed? Last question. Does the brand of lowering blocks matter or will any kind be okay as long as they are aluminum? And if so how do you do that? Sorry for all the questions but I am new to minis.