What is the fastest Intel processor that this model will accept?

I want to upgrade my mac Mini A1176 intel core solo 1.5ghz,

with 1gb of ram and a 100gb hard drive.

I would like to max this computer out. I am wondering what the best/fastest processor is, that I can install in it.

Also the max ram which I know is 2gb, but since it already has 1gb, should I purchase (1) 1gb stick or (1) 2gb stick and does it accept DDR3 ram or only DDR2?

I believe I can upgrade to a 1TB hard drive, is this true and will any 2.5" drive work?

Also will the SUperdrive from a 14" 1.42ghz Ibook replace the Combodrive which is already installed?

Thank You So Much.