I puchased the following element from Tobins (http://www.tobins.com.au):
1" BSP, 2.4KW 240V 350 mm penetration, screw terminals, SS316 water heating element with a metal terminal box 100 x 100 x 75mm : $190 ex gst each
Freight : $20 ex gst
The element isn't cheap, but fits perfectly and...