Question / Help Help me figure out my optimal output resolution to stream.

[insatings]

Hi there so I have a non 16:9 screen wich is the correct aspect ratio to stream on Twitch if I'm not mistaken. It is has a 1366*768 resolution so I believe that I have a couple of options considering that the closest acceptable resolution is 720p:

1. Stream at raw 1366*768 (wich I don't think is the best because of the "black bars" unless I stretch it, and because I don't have a 16:9 downscale resolution (720p for example))
2. Stream at raw 1366*768 and downscale 1.25 in order to get closer to a 720p resolution (meh)
   
3. Stream with a custom base resolution of 1280*720 but play the game at native screen resolution (best solution?)
   
4. Stream with a custom base resolution of 1280*720 and play the game at 1280*720 wich will look bad for me
5. Stream with a custom base resolution of 1280*720 and downscale if further performance needed

Basically my doubt is because the major guides out there assume people have a 1080p monitor and therefore it's straitforward to just downscale to 720p if they need to, and I can't do that since my native res is way lower than that so I would be glad if you guys could enlight me on this one :). Oh and I usually stream at 30fps, x264, 2000 max bitrate and buffer size, CFR turned off.

 

[Harold]

Stream base resolution of 1920x1080, downscaled to 1280x720, game capture source set to fit to screen, use overlay content to fill the black bars.