I say scream back, it may just get his attention. When my kids pitched a fit, I'd get right down on the floor and act out too now and then. It'll be a good release for you too! Oh, to see the looks on their faces! Course, you want to scream back in a controlled way to mirror his pitch, away from his ear, and have a good laugh with him afterwards. Scream, stop when he does, scream when he does, stop, scream, stop... watch his reaction. He won't know what hit him, but he'll realize the control goes back to you in short order. He'll also learn to laugh at himself, which is an important coping skill.
Two is not too young for a time-out either. One minute per year of age. Our spot was the bottom of the staircase in our foyer. When the time was up, I always sat next to my child on the stairs and talked it through. First, they had to offer me an apology. When they did, I asked, "And what are you sorry for?" If they could tell me, then I knew they'd learned the lesson. If they couldn't, then we talked it over and hoped it clicked in. I'd always end with a hug, which reinforces you love the child but don't like the fresh behavior.
Another thing that works well when the kids are frustrated, is have them go to the couch and scream into a pillow. It diffuses the angst, and just feels good to get it all out. It's easier on your ears too, then you can help him talk through whatever was frustrating him. I've done it myself a time or two in front of them to show them that even Mommy gets frustrated sometimes!
An important part of childhood is about testing the boundaries. So, best that you are prepared with discipline tactics ahead of time, especially since it looks like your son is going to give you a run for the money and maybe your daughter hasn't yet. A time-out routine is good. Once they can count, another great one is to say stop whatever behavior they shouldn't be doing, or ask them to do whatever chore you need them to do. If they don't do what you've asked, tell them you're going to count to three and if they don't do what you've asked by the time you get to three, there will be a consequence (be sure and have your consequences laid out in your head ahead of time, like time out, loss of privileges -- treats, TV or computer time, etc.). This gives them a chance to save face and make a good decision. Course, you have to follow through every time when they decide to push the limit. It pays off though. My girls are now 11 and 15, and all I have to do is raise the first finger and they get hopping!
Hope you've found something here you can use, good luck!