Well, seriously, I think the arrow that fits your description is a Microflite #5 or #6. They haven't made those in about 40 years, but there are still a few that show up now and then. There wasn't a tougher arrow ever made, in my experience. MJ Log fiberglass shafts were less tough, but also available in #5. This new Ferguson Heavy Hunter may be tougher, but .500 is their lightest spine as well.
If I were you, I'd pick the right carbon or aluminum shaft for the bow, and foot it externally with aluminum and suffer whatever damage occurs. Alternatively, you can find footed cedar shafts in the right spine, and they still cost less than FMJs.
Good luck!