So im shopping arouns for a new pads and rotors and i have encountered a problem. ECS says that there are 2 different rotor offsets for my model and I need to know which one to buy. How do I measure this?

I also came across someone mentioning an upgrade to a8 rotors and TT caliper carriers. Exactly what does this involve? Is it just a bigger rotor and a bracket that moves the caliper enough to allow it? Has anyone here done this?