Save up for as much live rock as you can afford (one box, for example). Use it to cycle your new tank, and cure the rock at the same time. After your tank is established -a few months- add as many nice pieces of cured LR as you budget for, slowly making your display into what you want.
Your tastes will change with time, and as you learn more about the needs of your own system, you will be able to hand-pick pieces according to these influences. It might be a year before you sit back and are satisfied with what you've created. Have fun, take it slow!
