I used to work hand painting mural work a few years back. Anything from kids bedrooms to shops and tanning salons. There were a few disasters that I remember, or at least ones that I think that were because I was working with another fella who had his own ideas, and then the client had their own ideas, and that sometimes resulted in a thematic mess. Obviously Liverpool is going to be the only theme here, I take it? I personally would tie in the entire surrounding walls with the same color scheme and keep it as unified as possible, rather than breaking it up with various different images with different color pallets. You could try that image above, only have it converted to a white vector over a red background. Sort of like a stencil image. That would save you money if you wanted it printed, or you could even paint the walls red and even possibly have it air brushed on if you're up to it?