First off, I have a question for you. Are you patient? If so, just get a small amount of live rock and the rest base rock. You could even do it with nothing but base rock. The more live rock you have the quicker you will cycle but it also gets very expensive.
The biggest key to rock is how pourous it is. The more pours it has the more area for the bacteria to grow. Other than that, go for what looks the best in your eyes. After all, it is your tank.
Oh, and one last thing.....we expect pictures.