It depends on what you like. If the kids are huge SW fans and not big character fans, then SW is probably better.
The SW show is movie images projected onto the theater set to music, with some lasers, and with a very few very small fireworks. To get a good view you’d need to get there at least 30mn early. To get a view on non-insane nights (probably from the street) you can just show up a few minutes beforehand but with short kids you’ll probably want to show up a bit earlier.
Since your group does not consist of die-hard DL Fantasmic people who have seen the show dozens of times, you’ll probably enjoy ours if you like DL’s. The seating is a huge plus. There are a few scenes that are different. What used to be a Peter Pan scene and is now Pirates at DL is a Pocahantus scene here. The show boat is a let down compared to DL, but it is still an excellent show. It’s usually pretty easy to grab a fp in the early evening for it, in which case you need to be at the tap point between 25-40 minutes before showtime. You are not guaranteed a seat if you tap in late. It takes a few minutes to get to the tap point after entering the walkway by the Beauty and the Beast theatre. If you’re doing standby, I would arrive at the entrance to the long walk to the theater 30 minutes early at the latest; sooner if it seems to be a crowded day.