Mine doesn't have a tilting screen, so there's not a lot I can say, since I didn't have that problem. I did help out another member who had a tilting screen, and that certainly had problems with it fouling the bottom of the fascia. There must be other members who have come up against this themselves though, and perhaps comment further ?
The trouble is that it's all a combined job really. You'll need to power the head unit to see how it goes with the fascia (fouling etc), and to power it you'll have to have it wired in (though not necessarily physically installed in there).
It's really not that hard, I know it might sound hard, but honestly, I'm kinda rubbish at this sort of thing but I did it fine. You can use a walkthrough to get things removed, connect up the new wiring (easy) and try the screen mechanism with the fascia test-fitted on. Then you can see what might need filing/cutting, if anything. Then you can sort out the fascia, fit it properly, and get everything put back in.
Another alternative that I can think of is to get someone to install it for you, but leave off the fascia completely. Then you won't have any issues with the screen, but you will be left with an ugly gap around the head unit. Although you can always plan to get that sorted later ?
You really don't need to pay an auto electrician, he'll be earning that money for doing pretty much nothing really.
I would offer to help you myself but Yorkshire is a little bit far from me. I wonder if anyone who is in your neck of the woods might be able to help you out.