I'm not sure about a sub but you can always use this;
http://www.isitdownrightnow.com/reddit.com.html
Thing is, if reddit was down the subs would be down also, so this is probably your best bet.
Don't know about a sub for that but I can share my basic knowledge (which might be incorrect)-
Changing the brightness changes all the pixels/colors by the same amount, and contrast changes them in relation to one another (the lightest compared to the darkest, etc.). The RGB settings are for correction of colors if for some reason the white balance isn't correct (if you have too much blue for example). Gamma I have no idea what it does (though you haven't mentioned it)
As for the best settings, it's really a trial-and-error thing that depends on the screens themselves and the room environment (lighting from lightbulbs/windows/etc.)
I can share my personal settings, maybe it'll help guide you-
(I linked you through a Redditor's affiliate link from his YouTube channel because he is awesome, but if you don't want to support content creators you don't know, you can always just copy and paste the item name into a fresh tab.)
What. the fuck.
I only found the name and artist via Shazam lol https://www.shazam.com/track/52857801/wonderland-original-mix
My second guess would be Wonderland (Peace treaty remix), but I can't find any official links :(