On a 30 gal
you would be fine with a 2x65 w PC
for most soft and LPS
corals. One white and one true actinic. Works great for my 27. As you said, different corals do not mix well and consideration must be given to those that are more aggressive. As long as you can provide a good 6" around each one, you should be fine but again that depends on type. Some need more, some need less. Posting a wish list when your tank is ready and after researching the needs of each might be an idea.
For the maroons, if you can find two that are still quite small, about 1-1Â½"; they will have a decent chance of becoming a mated pair and reduce the risk of buying larger fish that most likely will have altered sex by then. Unless you intend on raising the young, they will not be a concern. Might not sound nice but the fact of them surviving is quite low unless a proper rearing tank is set up just for them and the hatchlings transered as soon as they leave the egg sack. Most will be consumed by corals, other fish, pods
, equipment and eventually the parents. It's not impossible to raise them but does take a good amount or work and dedication. Once/if they start to breed, it will occure about the same time every month. Keeping up with that will be very daunting.