I need the graphics for a pantomime poster / banner / Facebook

I am involved with a pantomime society. Our next show is the classic, Jack and the Beanstalk. I need the fundamental artwork designed which can be applied to posters ranging in size from A5 to A1. The artwork will also need to work on a road side banner (2500mm x 1000mm), as well as Facebook banner. It will also get used in conjunction with our Facebook marketing, as some sort of background for cast images.
Attached is a crude example I found online: my expectation is for 'rolling hills', a beanstalk climbing through the title, clouds, and a castle sat above - with none of the other image elements in the crude example. The castle does not have to be huge, particularly if the beanstalk is done giving the perspective of reaching into the clouds, but it must be recognisable as a castle. Also attached is the poster layout for a previous pantomime, to give an idea of what needs to be on it PLUS this is the feel I am looking for, if you follow my drift.
It needs to be vector, editable format, 300dpi and in CMYK in photoshop or similar. The font will need to be confirmed.