Freerider,
Sisley Clothing in NSW are excellent, and their two piece suits are ideal for summer use, allowing the jacket to be taken off when you need to cool down.
The lightest weight (Nomex) fabrics are not always the coolest, since the density of the weave doesn't always allow body heat to dissipate as well as slightly heavier fabrics with looser weaves. Check with Sisley, they can advise accordingly.