Unless you want to view the freesat box remotely you don't need the triax unit or remote magic eyes. All you need is a simple loft distribution unit. You connect the terrestrial aerial to this and use the outputs to feed as many TV's as you need with the Freeview signal.
Without knowing exactly what wiring and kit you already have it's hard to be more specific.
If you have a outlet downstairs with a return cable to a loft amp. All you need is a TV splitter with one output feeding the local TV and the other the return cable. You will need to power the loft box in some way. You can remove the magic eyes as they will serve no purpose.