I haven't been there, but lots of people in my club drive up there.
Go for some larger pieces that feel a lot lighter than they look. For me, rock loaded with coraline doesn't matter much, because it's going to grow on the rock evenutally anyway.
I would say try to pick out some good sized branching pieces and some large flat pieces. Most of mine are boulder shaped, and I'm starting to hate them.
When you pick them out, try imagining where you would put them in the tank and how you want to stack them. Are you going for the rock wall look, or do you want it open with lots of space? Go for interesting shapes and whatever is pleasing to your eye. You might want to pick up some aquarium epoxy while you're there. If a rock isn't balancing just right, you can use some epoxy to make it stay where you want it.
Dry base rock shoved down in the sand makes a good sturdy base for stacking your LR on and keeps any burrowers/tunnelers from knocking your rocks down.
Do you already have a container set aside to cure them in?
