Keith Canham is still working on a custom order of Ektar 100 in 5x7. He actually regularly organizes custom orders of ULF film from Kodak in various sizes, including the exotic ones like 12x20 and 14x17. So it can be had, just not at the drop of a hat. You just need to plan (and budget) ahead so you can place an order for multiple boxes and then stash it. I bought two boxes of Portra 160 in 5x7 the last time B&H had it in stock. I would have bought more were it not $300+ a box (50 sheets). And now that I've tried C-41 at home (caveat: I have a Jobo, which makes life sooooo much easier), I'm not worried about having a lab locally to process it - C-41 at home, once you have temperature control worked out, is a piece of cake. If you don't have a Jobo, you can build a tempering box out of a large plastic tub, an aquarium heater, and an aquarium circulating pump. Keeping C-41 chems within 1 degree of accuracy is then pretty easy.