Actually if you decided on Aqara switches, you can use their hub and ditch the Samsung smartthings. Unless you plan to use other non Aqara devices apart from their switches.
I have Aqara switches and philips hue for my lights. For the bulbs, i have a mixture of philips hue, ikea tradfri and some third party hue compatible light strips i got from aliexpress as philips hue lightstrips are too expensive.
I'm mainly use iphonne and iPad so i have homebridge on a raspberry pi to have everything show up on homekit. you can consider home assistant if you are an android user.
For cameras, I'm eyeballing the Aqara G2 camera. Apparently, they can act as a hub and that might help to expand the zigbee range in your home.
BTW, i think Samsung don't make the smartthings hub anymore. It's now branded as
aeotec