Luci as WebGUI or what?

Will you be using Luci, just with added functionality or will you be writing your very own web UI that shall - at least partly - replace what stock Luci is doing?

This has been previously answered in one of their indeogogo update. Let me quote this for you:

Same as the original router Turris, Turris Omnia will have two user interfaces - Foris, the one we showed you last time, and LuCI, the default user interface in OpenWrt. While this might seem confusing at first glance, here are some reasons why we decided to go this way.

The most important reason is that while LuCI allows you to do a lot of stuff, it was not designed for the casual user. And because we believe that you do not have to be a network guru to set up a router, we have decided to build Foris. The main purpose of Foris is to provide a simple wizard-like interface for the initial setup of the device. It will guide you through the setup and when you finish it, you will have a fully functional, up-to-date setup which we can guarantee is secure. In fact, Foris will not allow you to connect your router to the Internet unless you at least provide a unique admin password, which deals with the most common problem of most home routers. And to keep the user experience consistent, Foris may also be used to change all the parameters contained in the wizard-like interface later on.

We believe that by arranging the user interface as we have done, we made Turris Omnia easy and safe to use for casual users, while not limiting the hardened network veteran in doing whatever he wants the way he wants - be it using LuCI, over SSH or using the serial console.