Dedicated servers for spartan ops please!

I cannot stand the 1 second lag time for everyone but host in Spartan Ops, and Co-op campaign for that matter. I want to play with my friends but this makes it downright impossible, it isn’t even fun unless your host and then the other people just get screwed over.
I have put up with it to get all my achievements and challenges but during episode 5 chapter 1 where you have to defend those stupid points my friends and I just could not complete that mission on legendary, due to this horrible lag nonsense. I wish that we could all sit in the same room and Lan party it but sadly they live in other states so that is out of the question.
So we had to just complete it in matchmaking which of course is only on Heroic for some reason, there is another problem, why can’t we have a choice of difficulty with match-made spartan ops. I would like to be able to find a game for legendary.