You can use most PTZ IP-cameras, you have to balance between quality/cost. Low cost is very low qaulity, both build and output. 4MP is good enough. Preferably dome, negative tilt (upwards) and 25x zoom. White balance is the main issue. Dahua and Axis is good (not great) on white balance. Example 49425GBNRis a cost effective permanent outdoor camera that may last for years.
You cannot expect to follow the skier, pan move is far from smooth and follow will be disturbed by crew on hill. You will have a reasonable good stream at 1080p or 720p, latency may vary between UDP and TCP.
For communication, use Unifi AirMaxAC to setup a ptp-link. anything from NanoStation and up. Remote control of camera PTZ via standard web.browser. Output stream to VLC or OBS, stream to web requires conversion.