Here is my list
YI This is a small cheap camera from Amazon. No subscription charge. I have an free app. I have the camera trained on the kettle. I can see a live view, or playback the last time she went to the kettle. I think this will be cheaper and more basic than you require.
I have a ring doorbell that shows me who is at the door and allows me to talk to them.
I have an Alexa show that can be programmed to say “there is someone at the door “ or something similar,
( only with the ring). Alexa show is also good for reminders, and video calls from family.
I have a Memrabel2. This looks like an IPad on the wall it shows clearly the time day date and if it is morning etc, it is very similar to a day clock except it gives reminders.
I have another day clock in the kitchen at exactly the place the medication is kept (medication pre boxed into am,pm, night cardboard containers by the pharmacy)
I have a guardcam outside it is an outside light that photographs all callers to the bungalow and has an optional voice alert the property is being approached.
I have a small metal sign from eBay warning all callers there is cctv inside and outside.
A carelink pendant, to be pressed in the event of a fall etc.
I can’t advise you on the systems above, but think I have heard of hive being good. I hope the above information isn’t too random for you, but you are obviously are taking safety seriously I chucked it in just in case any of it helps.