Ralph Moeller was a surprisingly good Conan in the Conan the Adventurer series.
Btw, in REH's lore Conan was described as being big but not the biggest, there were mentions of much bigger creatures/giants, however no other character was described as stronger, more agile, dexterous or skilled with sword.
While the new movie looks decent, Momoa is still not a good choice for Conan.