The original list I was building from used
Ragnar as the commander.
Ragnar is still the best option, I believe, but we swapped him out to fit the budget of the person I was building for. Out of the budget options, though, I think you're right;
Skyward Eye Prophets is probably better than
Rhox War Monk. Neither are very exciting, but 6 mana is easier to reach in pauper, and drawing extra cards has more marginal utility for a combo deck like this than 3 damage of
lifelink.