The link I provided, two of the cases completely cover all of the phone, instead of just having a clear film covering for the screen (which for your circumstances, would not suffice). With metal fixtures on the case. Those look like good options from that company.
Although it’s too late, knowing your work conditions ahead of time, maybe you should have opted for a more durable phone & not one with a large glass touch screen. Here is a cnet review of ‘durable cell phones’, a couple look like they could take a hell of a beating, even with no case on it. Just for future references.
http://reviews.cnet.com/4321-6454_7-6551600.html
You already X’ed out my other option, Otterbox, which no doubt they provide some amazing protection. So if you can’t find a tough case, I would say dealing with a troublesome screen protector, but having great overall protection is better than finding a less tough of a case with better screen protector. Hope you find what you are looking for.. good luck. I know what it’s like to worry about new tech. getting damaged. I didn’t open my new iPod until I had found a case to put it in.