Recommendation with motion detection events

[reallyphil]

I'm a software developer that's looking for a camera with specific features that I can use to build some software on top of. Specifically;

• RTSP (or similar) mechanism for transmitting a live stream
• Motion detection events, eg, via ONVIF Profile S or MQTT or something similar; I want the camera to tell my software when it detects motion
• Wifi 2.4Ghz necessary but a 5Ghz option would be preferred
• Good enough night vision to catch my dog sneak onto the sofa at night
• Happy with being locked off from the internet at the firewall level - none of this mandatory cloud/phone-home nonsense

Nice to have but not essential;

• mic
• PTZ
• Weather proof in case I want to put it outdoors some day

I'm in the UK and don't really want to spend more than £50 on this.

I've had a browse & search around the forums and see a few brands and models recommended pretty consistently, eg dahau/amcrest or hikvision - however I'm having a hard time a) finding them for sale in the UK, and b) determining which cameras would support motion detection events like I want. Some cameras list themselves as supporting ONVIF but don't really specify the exact capabilities. Motion detection events is an optional capability of ONVIF IIRC, so I don't think I can assume all ONVIF cameras will do what I want can they?

Can anyone recommend a camera that fits what I need?