Not that Sonoff devices are "great" out of the box for using them off the cloud, but they are pretty easy to flash tasmota onto them.
With HA there are a number of plugins that will allow you to easily setup duckdns&ssl, there is a app on both the Play Store and App Store.
EDIT: I run HA on a Rpi3 just fine, I also added a zigbee USB dongle which I use to control my TRVs. I also have some cheaper wifi sockets that could have tasmote flashed onto them, but they are a plain to open and access the pads needed to reflash them. The SonOff devices I've been playing with recently are easy to open and flash.
I also use shellys for my fixture lights, again easy enough to flash with tasmota so they are running off the local network.
OMFG ALL THE EDITS: Just make sure that the devices have a ESP chip in them before buying them if you want to reflash them. There has been a trend as of late of using other wifi enabled chips which tasmota doesn't support. Can't find the device on blakadder? Try https://fcc.io/ if you can find the FCCID (and your in the US) before buying the device and look for the internal photos, there is normally a pretty decent close up of the main processor in there. Also googling "The Device Name Tasmota" will often find results of other geeks trying to flash tasmota onto them.
Not that Sonoff devices are "great" out of the box for using them off the cloud, but they are pretty easy to flash tasmota onto them.
With HA there are a number of plugins that will allow you to easily setup duckdns&ssl, there is a app on both the Play Store and App Store.
EDIT: I run HA on a Rpi3 just fine, I also added a zigbee USB dongle which I use to control my TRVs. I also have some cheaper wifi sockets that could have tasmote flashed onto them, but they are a plain to open and access the pads needed to reflash them. The SonOff devices I've been playing with recently are easy to open and flash.
I also use shellys for my fixture lights, again easy enough to flash with tasmota so they are running off the local network.
Another Edit: https://templates.blakadder.com/ has a good list of tasmota supported devices.
OMFG ALL THE EDITS: Just make sure that the devices have a ESP chip in them before buying them if you want to reflash them. There has been a trend as of late of using other wifi enabled chips which tasmota doesn't support. Can't find the device on blakadder? Try https://fcc.io/ if you can find the FCCID (and your in the US) before buying the device and look for the internal photos, there is normally a pretty decent close up of the main processor in there. Also googling "The Device Name Tasmota" will often find results of other geeks trying to flash tasmota onto them.