Travelling back to the UK in a van (Madrid)

My boyfriend and I will be travelling back to the UK at the end of August and we're looking at the cheapest option for moving the contents of a one-bedroomed flat back to the UK. Using a van seems to be the best option, does anyone know of:
- a good one-way van hire company (based in Madrid!) ?
- a person who owns a van who is travelling to the UK at the end of August?
- another expat returning to the UK and who is also looking for a one-way van hire?
- a person arriving in Madrid with a van, who needs someone to kindly take it back to the UK for them?!

If you have any ideas, suggestions, advice, please get in touch!