Chambers for sure!
For some reason, I'm not too thrilled with Mason, he seems to play better later in the season.
Morton is a big bust so far, but it's too early to give up on him. I expect him to have a good day(5 catches, 1 TD) at home against a pathetic JAX defense. If not, he'll be in my doghouse.
I think the MIA@IND game will be a barn-burner, with Ismail again getting 1, possibly 2 TDs and 8 catches. MIA will be focusing on Harrison, which frees up Ismail.
I would start Ismail and Chambers.