12v Speaker System for Van/camper

Hi All,
previously I had a logitech stereo 2 speaker and subwoofer set. It had great sound and because it ran on a 12v supply from a small transformer I could remove the transformer and run it in my old car.

I'm building a camper van and would like to do the same with a more modern speaker system. The logitech ones are particularly powerful and it's a cheap way of getting a speaker system for the van that has units built round the speakers.
However not many speaker systems come with the 12v transformer,
I looked inside this set but it doesn't seem compatible:
http://www.komplett.ie/k/ki.aspx?sku=303910

Does anyone know of a similar or better spec'd pc speaker system they'd reccomend that could be ran from a 12v supply?

Thanks
Ronan