Hi Kiff
The Lumix FZ-300, the FZ-1000 & FZ-2500 all are well setup for video work -and- stills as we are used to
The -1000 & -2500 with the 1" sensor are larger & heavier that the -300. The -1000 zoom lens trombones out when extended, whereas the -2500 lens has internal zooming, so its lens barrel never alters in length during use
The -2500 has the built-in ND filter and if memory is correct, better v-log capabilities (but at extra cost to download the software). All have zebra patterning for exposure control during video use
The huge advantage of the -300 is its constant aperture F2,8 lens ... with it remaining at F2,8 right thru its 24x zoom range. In this case Panny have kept the sensor to 12mpx to avoid noise as much as possible, but as with every sensor (and film) if the light level is so low it and even our eyes are struggling, then coloured artifacts will appear
You might consider downloading each user manual to sqwiz the features and compare them with other possibles
Hope this helps
Phil