I wouldn't order any snakes from the east coast until we get a handle on the fungal issue. I'm still not sure that's what was happening with Underground, FWC gave them a clean bill of health, but I'd just stay away from those areas altogether until we know more about SFD. No reason to risk helping its movement to the west.
Kankakee Bulls are stunning animals, I considered one before deciding to stick with a Texas locale. I focus on natives as well, and Texas is my neck of the woods. Fox Snakes are very cool animals too.
Don't rely on what people tell you about your wildlife laws, go to the source yourself. I've even had game wardens give me bad information in the past.
Here is a link to the Iowa Legislature, Senate File 564, dealing with wildlife. I didn't read the whole thing, and it might not be all inclusive on the issue, but it's a place to start. I did notice they misspelled Viperidae, ha.