You will get a better price if you actually go there rather than email, that's always been my experience so always try to speak to people face to face if I can.
If you can't get it in your own car do you not know someone with an estate or something like that? Just rough cut it on site if the supplier won't cut it for you.
I have a people carrier but all the seats bar the one I need have been removed so really it's small van size. Seats just clip in so if I do have to ferry anyone about I just stick them back in.