Hello, Rider,
As AUS4 said, Neil Pryde make windsurfing specific wetsuits. The features that I have found of benefit on their 5000 and 3000 suits are:
Extra material in the forearm area to allow for forearm growth during sailing.
"Boomerang" (pre-shaped) arms, to reduce fatigue in the forearms.
Vertical, ? back zip for easy-on/easy off.
Wide opening near the ankles, sealed by Velcro, to aid foot insertion and easy foot removal when the wetsuit is wet.
Here's a link to their wetsuits:
http://www.neilpryde.com/wetsuits/mens/overview.html. Given your location, these may not be what you are after.
They also have a range called NPX and here's a link to it:
www.npxwetsuits.com/index.php?option=com_npxproducts&view=all&Itemid=85. You might care to have a hunt around their site to see if the wetties meet your needs. Am not sure that all of the features I value in the 5000/3000 are present in the NPX range.
Not sure if Reg/Windsurfing Perth keeps NP suits in stock, but Wind Surf n Snow in NSW supplied my 3000 model about 2 years ago, so you might send them an e-mail. I received excellent service from them, even though I was out-of-state.
Hope this helps.