Most stable ROM with fast WiFi?

I've tried a few ROMs now and they're all good except that they get buggy after some use.

All I really need out of a ROM is stability and WiFi speed. Is there a go-to version in this regard?

Android version does not matter, robust features does not matter either.

The only features I need:
-Stability after long use, and without restarting for a while
-Reasonably quick WiFi
-Ability to install Dolphin or Firefox APK

I literally just want to use a web browser on it and that's it.

Any help here would be appreciated