Fitness/Sleep tracker that wakes me up in light sleep cycle?

I am looking for a smartwatch/fitness/sleep tracker that wakes up me:

- Ideally when I am ready (if such a thing exists) OR

- In my light sleep cycle based on my alarm setting

I have looked around but did not find one that meets my needs. Using Fitbit which uses light vibration, but the best option I found ironically is simpler gentler sounds like `Circuit` on my iPhone.

For the context, I don't drink alcohol, no caffeine intake post 7pm, no electronic devices or TV post 9pm, sleep around 11pm, with night blinds. So trying my best to give myself some quality sleep :-).

Any tips on a device will greatly help, if not someone on HN makes it :-), Thanks!