2 cans to lug around on a 400 is silly in modern day terms. I understand why you would want to remove it.
Ebay is your friend for your bits. I know SA doesn't have ebay, but you may get some stuff shipped from the US?
Some of the gsf400's came with a stainless oem system that sells for cheap money, and it was this I was trying to suggest not a $$$$ stainless system. GSF400 non variable valve models are very similar to your engine, which is really helpful as it gives another bloodline of bits, where as the poor old gsxr400 gets abused to the worst degree, and the quality of bits is usually sh*t!