The longest is defintely Kalamunda to Dwellingup. It is possible to get a meal at Mundaring Weir if you time it with the Pub. A popular option is to spend 1st night at the Hotel or YHA at Mundaring - halfway between Hewitts Hill and Ball Creek huts.
Also possible to get a meal at Nth Bannister Roadhouse but not supplies. If you contact them I believe they will hold a parcel for you.
In my case I travelled fairly fast (36 days), had my son meet me at Nth Bannister, and for the rest ate mostly noodles etc between towns.
You can eat big in Dwellingup, Collie, Balingup, Donnelly River Village (sort of), Pemberton, Northcliffe, Walpole and Denmark as well as resupply at those points.
You can also generally get a meal at Peaceful Bay and (depending on time) at Munglinup Tavern.
I would recommend carrying about 5 days worth for the longest sections with what I refer to as "hold out meal" of one of your favourite dehydrated meals. This can be had on last day as a reward, as a "pick me up", or as emergency meal if you misjudge.
You probably will need a food drop or a friend to help out at Nth Bannister (Gringer Creek) unless you want to travel with 10 or so days worth though.
If you have no locals to call on for help PM me with the dates you expect to go and I may be able to help. Nth Bannister is easy for me to go to.
