Hi there,
The requirements are quite clear and straightforward to implement. Apparently, there're 2 options to create the msi installer, wix or nsis. I have used both in other projects. Nsis offers a more direct approach and most of the time gets the job done. Wix on the other hand is a monster but there's pretty much nothing it can't do. I haven't built the mentioned system, nextcloud, before so it's too early to pick one but as I've said nsis will probably be enough.
Also, if you want to sign the final installer you'll need to buy your own certificate for that. If you go with your own certificate your designated name will be displayed as the publisher on UAC modal window which is shown to the user when an installer is run on Windows.
Anyway, per your requirements, your designated name, icon, logo will be displayed everywhere; on installer, add/remove program list, ect. everywhere. I expect this to take at least a week, thanks.