All the above... plus, 3x4 slotted film holders still show up on eBay. As do expired 3x4 film sheets and 3x4 film packs. Alternatively, you can grab some cheap 4x5 Arista/Fomapan and cut it down to 3x4. Yes, it's wasteful, but it's only Arista.
As far as shutter speeds, I took mine to a local camera shop and paid $20 to test the speeds. Some were on, some were off, but at least now I know what I'm shooting. The repair guy cautioned me to avoid the higher tension speeds if I could... saves wear on the ancient spring. Also, if you're going to store the camera for a while, he said to release the tension back down to Low, and the shutter down to 0.