IMHO if you use cured rock from the start at a rate of at least 1 lb per gallon you will not really have a traditional cycle. By using the cured rock you are adding an established biological filter from the start. The only issue is that I would caution against adding fish very quickly. The bacteria will die off if there is no ammonia to consume. Using this method I would still let the tank sit without any critters for 2 weeks while testing the water making sure you do not have any die off. After this period you can begin to add fish at a rate of 1 every 3 or 4 weeks to allow you bacteria population to grow along with the waste load.
I would not add cured live rock to a tank that you plan to fishless cycle. The ammonia load will kill of some of the life on the rock that you paid handsomely for.
You can also fishless cycle using uncured live rock. If you purchase uncured live rock, you can cure the rock and complete your fishless cycle at the same time. The die off from the uncured rock will provide the ammonia necessary for bacteria growth.