There are some beautiful patterns around, even from the seventies. As long as you dont clad the entire walls and ceiling in wood panels i think the 70s has some parts worth retaining.

Try Sparkk. www.sparkk.com.au They have a huge range of digitally printed designs that are customizable for fabric and wallpaper. . . all printed in Sydney. Good luck!

I see wallpapered ceilings a bit in photos. See example. I can't imagine that would be easy to do! An application I did like was wallpaper between dark painted rafters. It was really effective. I don't envy the person who had to do that job. Or anyone who wants to remove it later. In my previous home, every room had been wallpapered sometime in the 80's. All bedrooms, hallway, living room, kitchen, bathroom, toilet. Quite a process to remove! I don't mind wallpaper but I didn't like the ones in that home. I think wallpaper can work really well in homes with a grander scale. High ceilings, architectural trims etc. In smaller homes, a restrained use is more appropriate IMO.

I think  wallpaper mural style or otherwise is a really bad idea on this wall.  It's already a very busy space and tv on a busy background will make it worse.  The fact you don't know where to finish it tells you this is a wall where it won't suit.  Save your money.