This thread missed my attention. Thanks Kymmie for pointing it out to me.
The link above to my 180 build thread will give you a ton of answers to this issue. I spent quite some time explaining my curing process for live (or dry) rock and posting pictures.
Rock from different areas can be mixed. You will find the Caribbean live rock to be higher in density than the Fiji rock, which means you are getting more rock per pound with Fiji. I also think the Fiji rock is more attractive in shapes and texture. As for color, within 5 or 6 months inside your aquarium any rock you purchase will have dramatically different color and life showing than it did at the time of purchase. I would focus more on texture, shape, and size.
Rock from any part of the world is likely to have "nasties" inside of it.-) You will find that dry rock is free of these critters, but any live rock runs risks. These risks are minimal and not the slightest concern, in my humble opinion. I do suggest that you take the time to observe your live rock prior to adding it to the tank. Placing the rock in a curing container, as seen on my 180 thread, can give you ample observation time. This curing time also allows you to test for nitrite and ammonia to ensure the rock is actually cured.
I want to discuss your comments above. You said that your tank is "cycled". What do you mean by this? What is the biological media you have in your tank? Regardless of your answer, I am going to suggest (very strongly) that you remove the biomedia and only use live rock (or dry) and live sand as your form of biological filtration.
By the way, I have personally used Marco Rocks The finest aquarium rock available, base rock, live rock, reef rock, marco rock, reef tank saltwater fish, live corals, Marco rocks, Fiji live rock, Tonga Live rock
to purchase the large majority of my rock for my 180. They are a dry rock provider and the quality is excellent. I do not consider this rock to be "base" rock. Look at the pictures in my thread as this rock has become live over the last several months, and you will see why I continue to recommend this site.
Finally, you need a protein skimmer. You don't have to use a sump, but you do need a skimmer. The skimmer is the single most valuable piece of equipment that you will purchase. For your size aquarium, here are a couple of skimmer options that hang on the tank: Berlin X2 Venturi Skimmer | Venturi Models | Protein Skimmers | Aquarium - ThatPetPlace.com Super Skimmer with Needle Wheel - Up to 65 Gallon | Venturi Models | Protein Skimmers | Aquarium - ThatPetPlace.com
Keep in mind, the protein skimmer should be your most expensive purchase because it is your most important purchase. Each of the skimmers above will handle your tank. The Berlin is capable of upgrading to a 75 gallon tank in the future, should you so desire.