General questions are tough to answer well in this format IMO, but here's a few of my thoughts...
Recreating a certain biotope is cool idea - certainly worth considering. Many people just tend to put things together that are generally compatible, regardless of origin and that's fine too. I'd recommend checking out local reef stores, books, doing searches online, etc. to get an idea of what you'd like to keep first. Once you have an idea of where your interests lie you can setup the system to best suit the needs of the animals you plan to have.
For example, if you're interested in having a Hippo Tang ("Dory") some research will reveal that they grow fairly large and require a large aquarium for long-term success (say 100 U.S. gallons or more). Oscellaris or Percula clownfish, on-the-other-hand, are generally fine in smaller aquariums and if you get a pair of juveniles you'll likely end-up with a breeding pair eventually.
As for corals, for a first reef tank, most start with soft corals because they tend to be hardy, undemanding and tolerant of mishaps with water quality. For example, there are many colorful variations of zoanthids, mushrooms, star polyps, etc and all tend to be pretty easy to keep successfully. They're generally easy/cheap to come-by as well. People tend to graduate to the more demanding stuff in time.
HTH