Here's my 55 gallon set up. The rocks are granite cobblestones I got from menard's and some I found around outside at work. The 2 rocks in the middle are texas holey rock that I paid way too much for at the LFS.
Very cool rockwork.
You have given me many new ideas.
Iv'e only had our tank going for a short time and am not completely satisfied with the results so far.
I'm slowly eliminating the Malaysian Bogwood in favor of rock as it is a lot easier to keep clean.
I suspect that as the fish mature I will need to rethink the whole setup to provide more/larger caves.