Crust help

I've been after that same crust too, it's part of what keeps me baking and learning. The more I try and learn, the more I believe what you are after illustrates the difference between home and commercial baking technology & environments. Commercial bakers manage their baking environment in a much more scientific, controlled way; they must do so in order to get a consistent product. They use dough conditioners, water filtration, temp-and-humidity controlled proofing boxes, and steam-injection ovens to create a specific product day-in and day-out. They know how to make adjustments to control baking variables as needed to maintain that consistency. We can try to replicate a lot of these techniques in a home environment on home equipment, which gets us close, but often not close enough. 

That said, a few questions/suggestions for you:

1. What temp do you bake at, and for how long? 400-430F should be good enough; it appears thats what commercial bakers use to get those kinds of crusts. Lower or higher than that could be a problem. Timing is key too: the more moisture is left in the crumb after baking, the less the crust will stay crisp. Make sure you bake long enough ("long enough" depends on temp, loaf size and other factors)
2. Some crust steaming or washing is necessary. Spraying loaves with a fine mist of water before loading can help. Or egg white wash. 
3. What kinds of fats are you using in your loaves? Too much could be a factor.  
4. What loaf shapes are you using? It will be easier to get crisp crust on smaller loaves (think baguette or ficelle) or rolls than on big boules or pan breads. 

Like you, I've had some good luck with rice flour, using txfarmer's formula for po-boy sandwich breads. Still, that flaky, shattery crispness eludes me as well.