There are actually quite a few "easy" SPS
or at least not so difficult species
Before you move onto those though I would be sure you have a good grasp on your tanks chemistry. Monitoring regularly and have thought out a good maintenance routine for dosing alk
. Once you start adding a decent amount of scleractinians, the demand on the CaCO3
will shoot up quite a bit.
That said though I would look into types like Montipora, Pocillopora, Porites, Pavona, Stylophora and the like. For the first while anyway I would avoid Acroporids. They can be a bit more challenging but given the right equipment set up and proper tank maintenance should give you no more trouble than any other coral.
One thing to be cautious of when adding new stonies to the tank is start them out as low in the tank as possible for the first few days-week. They need to light acclimate as much as to the water chem. If placed to high in the tank too quickly it can cause bleaching. After a short time period you can then inch them up every few days until they are in a good spot and can be secured with epoxy of cyanoacrylate based super glue gel or both.
If your going to keep a mixture of coral types ie... soft, LPS
; I would be sure to use carbon as often as possible or 24/7. It will help remove any nematocyst or other chems given off by corals when they are looking for "growing room" or something has gotten too close. It will help avoid RTN