Is the video slate the same thing as an offline screen?
Most basic packages offered by a company specializing in streamer graphics generally includes:
- Facebook, Youtube and Twitter banner (I also believe the Twitch banners have been removed). These banners are generally a single graphic resized to fit the individual requirements of the specific site.
- Some combination of offline/starting soon/brb/changing games screen for Twitch.
- 1 custom overlay
- 3-6 Twitch panels (about, pc specs, rules, schedule, other similar headers) as mentioned by @lyteforce
And that should be everything you need to get started with content creation on the major sites.