I would start Moore for sure likely as your #2 WR, he had a bad week last week but I think they will be throwing the ball and he is good for a score today.
Then it gets more difficult.
I would lean D Jackson because I think they will be just ok running the ball and he should get one long TD to go with a few more receptions and turn in a good game overall.
Although Blackmon is also intriguing to me for todays game. I could see either Blackmon or Jackson as your flex, I think both will be nice starts.