The seats are made by AutotecnicA and are available Locally. An Autobarn near you probably have some you could try out for size.
AutotecnicA.com.au » Seats, Race Seat, Monza Seat, Racing Seat
The model number is A1098
One good thing about them is they don't come up as high in the hip area as some others. I'm 6' and 100KG and they don't fit me too bad where as many others are a squeeze.
If your local shop doesn't have on on display I'll drag one out and take some measurements for you.
Cheers