my Dad found this one
www.tekseating.co.uk/contact.php
along with Nick he wanted a seat raiser for his van passenger seat...£400+ and then vat from peugeot...£95+vat from here...they will also make you up specials

whilst looking for something, also found this place that does a lot of seat bases for loads of vehicle

http://marcleleisure.co.uk/Seating/SeatSwivels03.htm