Folding seats / sleeping platform

Hi All,

I'm looking at putting a sleeping platform in my 90, at bulkhead level extending over the passenger seat. At the moment I've got some Audi S line sport seats thanks to a previous owner, and whilst they are comfy, they don't fold flat.

I know original seats will fold relatively flat with the head rest removed, but can anyone recommend any other seat manufacturers that they know will fold flat?

Thanks