There is a huge thread on related text to use so you should skim through that!
As for relatng to Coleridge- just form a statement (Thesis?) about what you think imag. journey is and prove it with techniques used in Coleridge and your related material.
So, you need to find a related text that fits your own statement. I have a friend using Chapman's Homer by John Keats and relating it to Kubla Khan. Or maybe Pink Floyd songs- i think there is one called Learn to Fly which can be related to Lime Tree Bower (metaphysical experience). As for "sophisticated text" - children stories are the best imag. journey it's how you discuss it that makes it 'sophisticated' or not!
Anyway, have a look at the huge thread on related texts because you're sure to find one there!
Good luck
