Continuous Integration infrastructure for multiple iOS projects
Is there any other viable solution, maybe better than the ones above :) ?


For Jenkins probably no, due to the license issues you mentioned (you have to run macOS on Apple branded hardware). If you can work with that then it's definitely a solution.

If not, then I'd suggest you to check for a hosted iOS continuous integration system where you don't have to deal with the Apple hardware / licensing, the service will manage it for you, e.g. https://www.bitrise.io

There are also services where you can rent Apple hw and you can configure it any way you like, https://www.macstadium.com is one of them (probably the biggest one).