I wear the Haix Airpower X1 EMS Station boot with the front zipper.
http://www.haix-bootstore.com/rescue-station-boots/airpower-x1-us
They're pricey coming in at $260 a pair ... however let me through this out there.
I bought my pair four years ago. I've had them resoled once ($70) so in total I've invested $340 in my foot wear in four years.
The boots are amazing. They are EXTREMELY comfortable. I can run a 24 hour shift in them and have no problems. I can stand on my feet for hours without any pain or discomfort. They care completely water proof and have saved my feet from falling O2 bottles, the stretcher, partners, monitors, doors, walls, and other weird and unforeseen events. The sides of the boots have saved me from spraining my ankles on numerous occasions. I can honestly say without them I would have done some serious ankle damage. I sleep comfortably in them and when I do want to take them off they're extremely easy to put on and take off. They fit like a glove! I would HIGHLY HIGHLY recommend them to anyone who is looking for an excellent pair of boots. Yes, they're expensive, but justifiably so. In the long run they've saved me money and even if they didn't, the comfort and protection they've brought my feet and my ankles is well worth the money.
Thats my two-cents worth.
PS. I get these boots in the mens, but the ladies boots are also comfortable. I have a wide foot and I didn't like the narrow feeling of the ladies boots. One of my partners has the ladies airpower x1's and she loves them.