Meet me behind the outcrop. I'm a little boulder there.
You are going to need a REAL swing for two children...with a seesaw type thing AND a sliding board...set up with two bars between the supports for "skinning the cat".
And you are not going to be able to wait two years to get this.
Don't forget about the swing dad made you! If you hooked it up on something similar to what Mark did for ours, your whole family should be able to fit on it and swing away!