K.K.
HI H., You should definitely invite all the family members. They shouldn't be mistreated just b/c your FIL is a jerk! I think that you invite everybody and be the better person by not saying a word about your falling out. I mean, your FIL probably thrives on the drama and the more you say, the more he thrives.
Plus, you should invite your MIL. Just send her an invitation by mail. If she doesn't come and people ask why. Say I don't know?? That way, your in laws look like the bad guy instead of you. At least you have invited her and the ball is in her court. If you don't invite her or the other relatives, then you are the bad guy.
Good luck!