I cant answer all your questions but I will tell you this. The prevailing winds in this part of Australia (due to the polar vortex) is always West to East. Riding East to West will be committing yourself to a Headwind the whole 3,700 KM.
Good luck on that.
Everyone rides it Perth to Sydney.
And yes, you will need a lot of supplies. Not something to take on lightly.
And,
Due to COVID-19 you won't be allowed to do it at the moment anyway.