Why do you think a wall hanging flat aerial would be best, if it was then this is what everybody would have on the outisde of their property's.kidloco said:you will struggle getting a good signal from an indoor arial but I believe the best ones are the wall hanging flat panel ones. You can get them from quite a few places online.
Another option that might be worth a try is putting an outside arial in a cuboard. Thats what I did and it works great.