Yeah, I see the subscription stuff. I found some wheel art. I really just want some screen shots for each game. I don't care that much about themes and videos and such, but for some reason I can't find a simple screen shot pack.
Before I decided to pay for the subscription I used google images and searched for "game title" and specified in the advanced search that I only wanted .png files. It's a bit time consuming, but if you only have a handful of games then it might be your best bet. Download the .png and throw it in your Wheel folder in HyperSpin with the exact rom name and it will show up in HyperSpin.
As far as themes and videos go. HyperSpin provides a program named HyperTheme (I believe). You can open this up and make general themes for your emulators. I enjoyed tinkering around with it, but again it can consume a large chunk of time.
The videos used by HyperSpin are .mp4 I believe. One way to go about it is to download youtube videos and insert them as game vids in the Media, Video folder. Just rename them the same as you rom extension and you are good to go.
If you just want a screen shot for the game and don't want to pay. You could make a Theme for each game and find some standard images online. Just insert the picture as a background and omit the video playback feature.