I was going to get the Sony a6300 but than i realized it has an overheating issue than I was going to buy the Sony a6500 but that doesn't have a headphone jack I was just wondering from anyone that knows a lot about cameras can guide to me find the right camera that is 4k resolution, great in low light has a very few cons and has a headphone jack. My budget is no more than $1000 - $1800, mainly going to be used for filming.
For video work the best cameras are not the Sony's (which are pretty good). The better choice for your application is one of the Panasonic GH series. 4k capability starts with the gh4. There is a newer gh5 as well, but it is more money (nearly 2000 vs 960 for the gh4). The video focus speed in the GH series is the best inter-changable camera I have used. Also the gh series is the ONLY still image camera which allows for videos of over 29 minutes.
If you can live with manual focus in video (like the Pros do) and you can live with takes of 29 minutes or less, you will get better results with a larger sensor. The very best results would be with a Sony a7s II, but it costs 2600. Something like a used Nikon or Canon would do very well. I prefer Nikon, many prefer Canon.
If AF and recording length are concerns, you won't do better than a GH.
I own an a6300 and love it. I pair it with a Panasonic G7 which is a cheaper alternative to the GH4/GH5.
I have had a few issues with the overheating on my a6300 only when shooting in 4K. I was shooting outdoors (under shade) in Australia in about 28 degree dry heat and the camera recorded for about an hour and a half before needing to be be cooled for about 10 mins or so. I got sporadic 20-30 minute runs after that. It was rather annoying. Apart from that I have noticed issues with rolling shutter from time to time but I mainly shoot stationary on a tripod so I can avoid that most of the time. I do recommend the a6300 whole heartedly if you can get over those issues and work around them. If not, as Bjornl said about the GH4 is a great camera. You could pick one up second hand for under $1000USD now that the GH5 is out in the world.
If you want a brand new camera the Panasonic G7 is the little sister to the GH4. The G7 houses the same sensor size and takes M4/3 lenses also. The main difference can been seen in the build quality that is considered much more 'plasticy".
Other options are Sony or Panasonic camcorders. I am not familiar with them, but I have a few friends who swear by the sony UHD line of camcorders.
Anyway, I hope you'll still consider the a6300. There are no perfect cameras and you'll always have to live with one weakness. The a6300 is a beautiful camera if you are not going to be flailing the camera around much.
The issue with the a6300 would be recording length and eventual overheating. Also it does not seem to focus as fast in video as a gh3 (I have not used the gh4, because I don't need 4k)
The issue with the g7 (for video) would not be the low build quality but the recording length.
The issue with most cam-corders in his price range is sensor size and the resulting low relatively poor performance in low light.
FYI: for my use (which does not match the OPs use case) I use a GH3 for events (concerts, live streaming to a large venue, etc). I use a Sony rx10 for sports (American football, for example) is played in the rain and there are plenty of stops in action where I can stop and restart the recording to get past the 29minute "per-take" limit of any camera other than cam-corders or GH cameras. For very low light or when I am trying to get very thin DOF I use a full-frame Nikon (D750), but focus is generally manual.
There are different cameras which do different things. The tricky part is trying to find the one that best meets your specific uses.