There are a few places in Visalia to get food and gear. The best option is Sport Chalet on Mooney Blvd just south of Caldwell. They have a big selection of both food and gear, approaching the level of the Fresno REI. There is also a Walmart across Mooney from Sport Chalet and they have a few choices of freeze-dried food. There is a WinCo on Caldwell about a mile west of Mooney, and they have a few different kinds of bars (things like Clif) but I don't recall seeing freeze dried food there (that is where I do my grocery shopping). Bear in mind that WinCo does not take credit cards, but will take debit cards.
I always use a canister, even when not in a canister-required area. They are so much more convenient than trying to hang food. And protection against marmots and rodents is important. Those marmots get pretty aggressive. If you are going for eight days it will be a tight fit to get your food in the canister the first night, you will need to repackage the freeze-dried food in ziplock baggies. If you are renting canisters, remember that the Garcia is 615 cu in and also has a design that makes it difficult to make full use of all 615 cu in because it is hard to pack the final portion in the top just inside the lid, around the rim of the canister. The Bearikade weekender is 650 cu in (I use one of those, and it has worked for me for up to nine days). And the BearVault is even bigger. If your itinerary takes you to places with bear boxes the first night or two you can use those. Unless you are taking a route that is popular with horse packers, the bear boxes are usually available. Kearsarge and Charlotte are popular with horsepackers, hence the stories of finding the boxes full.