Moving right along.....I've discoverd that Astra Image,
http://www.astraimage.com/, has a version as a photoshop plug in that reads FITS. It's version 3.0PS. I've sent off an enquiry as to whether it does 64 bit and also QHY-style OSC FITS. Probably won't see a reply for a day or two (they're in Rosebud, Vic).
In the meantime, has anybody used this particular program in its PS version?