I use Aqara motion sensors. They are cheap (Ali express), battery operated (can put them anywhere) and have always worked for me.
They are ZigBee, so the caveat is that you will need a dongle to use them. Mine is a Zig Ah Zig Ah from ElectroLlama and cosy under £20.
The reason I moved from WIFI to ZigBee is for reliability. WiFi just isn't reliable. Any mains powered ZigBee device (bulbs, switches) are also usually routers, so the signal can be bunny hopped between nodes in the ZigBee network, unlike WiFi.
Also yes, one of the beautiful things about HA is that it is the middle man between many many different manufacturers of smart home appliances, so if you automate your main lights you should be able to add in a plugged in lamp to the automation.