Hi. We publish books.
They are in hardback or softback, or (usually) available as both.

What I'd like to be able to do, on the product page, is have one picture, with the hardback details and price, and also the softback details and price, and allow the client to buy one or the other.

There's a thread here
http://www.zen-cart.com/forum/showthread.php?t=96727
which looks like it might just work, but I'm not sure.
Any advice grovellingly accepted....