The 14700K and KF are a very recent refresh of the 13700K.
They should be priced similarly, and they should perform a little better in productivity applications, and have some extra features (e.g. https://www.intel.com/content/www/us/en/support/articles/000095419/processors.html). Unless you can find a very good price for the 13700K, pick a 14700K or KF.
The 14700K includes a built-in GPU which the KF does not. Some streaming applications may use it to encode your stream, and it may help in some other applications (e.g. Corel Painter) if you use those. It may also come in handy if you have a discrete GPU, but it fails, and you need something whilst it's being repaired or replaced.