I do not know much about any particular outfitters, but stick to zone 4 or 5. Iowa hunting is amazing. I have property in Zone 4 near Lamoni, IA and I have seen bucks every year in that area that will gross over 180 inches. I only get to archery hunt every 3 to 4 years but its still fun to see them.
I would second J&S Trophy Hunts for Iowa. They have been taking few hunters the last couple years so the bucks are growing big there. Worth checking out. Last season only had 10 bowhunters - 5 shotgun hunters - 3 late muzzy guys so pressure has been light so many large bucks available.