That's a green Elkhorn Montipora in my icon image. IMO most Monti's are great SPS for beginning since they are extremely hardy and easy to care for. That one is more than 25 years old, and has survived several tank disasters. Montipora Capricornus are also quite easy to keep and usually very fast growing. I'd avoid any polyps or colony corals for now, although some zoanthids may be OK if you keep them isolated on their own rocks. Colony corals like star polyps, mushrooms, Xenias and the like can very easily get out of control and take over a tank. Ricordias are somewhat of an exception, as they generally grow and multiply more slowly. Caulastrea (and actually, most LPS) are generally hardy corals, and most do well under lower light conditions on or near the bottom of your tank.
I'm not a softy fan, but many people start out with them. I was never able to keep them long term.
I agree with the OP's intent of starting out with 4-6 carefully chosen, non-aggressive specimens. Place them appropriately, give them plenty of space and see what happens.