NFPA 70 is the regulatory code. UL is not a regulatory authority, it is an approval and certification agency. Local jurisdictions have authority over code adoption and enforcement but they universally adopt NFPA70 and occasionally augment it but very rarely countermand it.
NFPA 79 is a subset of NFPA 70 that pertains to industrial machinery and I strongly recommend getting a copy and using it. Google NFPA 79 to find dealers. NFPA 79-2012 is the current version. I think that the 2007 version of NFPA79 is now available as a free PDF and that should help you a lot to get you to where you need to be.
We sometimes ship machinery to Europe and sometimes import machinery from Europe. From my experience the biggest hurdle is going to be the 50/60hz frequency difference, and even that is not a big deal. Motors will rotate faster on 60hz and draw slightly less current. Transformers are a little more efficient at 60hz so secondary voltage will be slightly higher. Avoid using 230V control voltages - while 230V systems are common, it is not a common control voltage and replacement parts may be difficult for customers.
Fuses - Euro bottle style fuses are not common here and are difficult to find. On the other hand, 5x20mm fuses are very common.
Breakers - Some Euro din rail mount breakers do not meet code for primary branch circuit protection (not robust enough) and are only suitable for use as supplemental protectors. Look for UL489 markings on din rail mount breakers used as primary branch circuit protection.
Wire sizes: Always convert up in cross section and down in current rating. For example, 12 gauge wire has a cross section of 3.31mm2 and is rated at 20 amps. You will have to convert up to 4mm2 wire, which is bigger, but still protect the wire at 20 amps as though it was a #12 wire. You'll find that some wires sizes favor the IEC ratings while some favor the NEC ratings.
