React Semantic UI
Offers all benefits of Material UI and some more customization options. What's more, it's not as cliché.
https://react.semantic-ui.com/
Going to build out and host all wireframes on whimsical.com.
Links will be placed in Mockups
https://whimsical.com/9xUF85kKJFF8c5TE1zdEpE
Design system will most probably come with a designated font in place. Nevertheless, we can opt for:
Final Decision: Lato + Karla
Generated via https://colors.eva.design/
Primary Color: #46d2a3