Hello and Welcome to TFP!!
Exciting times for sure. Lots of talk about safety in the comments and rightly so. Whatever system you choose needs to be passive. Kids are very creative when it comes to getting around barriers to reach something they want. You can't rely on door bells or wrist bands or "keeping a close eye on them"
As much as I see the benefit of having "puddle jumpers" on the kids, I think it adds a false sense of security. You put the jumpers on when they are in the pool with you right? But that's not when they are really needed. When we installed the pool, we had 3, 6, 8 year olds. None swam much except at a beach. Guess which one was able to swim the best? It was the 3 year old. the older one could touch and cheated his way around the pool. The middle one bounced like a pogo stick around. The only way the youngest could get off the ladder was to swim. He had a lot of incentive. Jump off the ladder to Dad and then Dad made him swim back. Repeat... Playfully toss them in the air and let them swim back to you. Don't get me wrong, I gave my wife a heart attack a couple of times, but the kids came up laughing. The kidos need to feel comfortable in the water with their face underwater. That way if a slip happens, they don't panic and instinct kicks in. Teach them to blow bubbles with their face under water. Teach them to lay prone on their back and how to roll over to get on their back. Make it fun to learn these. Practice in the bath tub.
Use a ladder with a folding legs that can lock upwards. Keep chairs away from the pool edge.
Read
ABCs of Pool Water Chemistry to get an idea of how to take care of the pool water. Start a thread in the
AGP section and we can give you some advice on the equipment and care of the pool.