Where to file and processing time
 

I'm considering to start the GC process through employment sponsorship (my employer is willing to). However, before I move forward I would to understand more about the process. My specific questions are:

1) Where does ETA 750 need to be filed if
a) My employer is located in NJ
b) I live in TX

2) Which of these states have the fastest processing times, assuming that ETA 750 it is filed in the state where the sponsored person lives
a) New Jersey
b) Missouri
c) Texas

Thanks much.