I've come across chairs like this, often child-sized, on ebay and various vintage websites, but the Sansone Chair from Daniel Lawrence is brand new and adult-sized.
The seat is made from rattan with a distinctive round back that gives it a 1970s look. It is mounted on a metal frame. There is a rattan table to match, which would be ideal for using as conservatory set, although I like the chair just fine on its own as an accent piece. It costs £160.
Visit Daniel Lawrence to buy.