h4 spouse ead for physician on J1 waiver job

[chand_m16]

I am a j1 visa physician in trainng , and plannig to start a waiver job in sept 2017. I wanted my spouse to get an EAD after i140 approval .. When is the earliest we can ask our employer to file for i140 premium processing (via perm process) or File an NIW..

Can it be started after j1 waiver is appproved.?

Or I have to start employment first.. ?

And do i need a 5 yr contract signed right at the start for i140 petition under NIW.. ? OR I CAN SIGN A 3 YR CONTRACT AND EXTEND IT LATER..