If I remember correctly, 9.5" (or 9.7" ?) roll film was still being sold by HAS imaging in Ohio until recently. Maybe you can still get some panatomic x or such.

If I were shooting ULF, I think I'd look into coating my own dry plates and let the charming little defects fall where they please. I don't see much reason to use a high quality / high price film for something that's just going to be contact printed. But that's just me. I do need to get my 11x14 moving. Time to bite the bullet and learn how to coat!