If it were me, I'd start off with the pair of clowns. Sturdy little fish and I happen to have a bad case of clown love. I have 2 pairs so far. I want a third set. lol
Do you know what kinda clowns you want? I am partial to the black & whites
The watchman combo sounds good, I tried it in my 55g but the shrimp and goby never hang out. It happens that they dont form a relationship i've been told.
The only thing that I'm not sure you know is that sun corals, while super colorful, require actual feeding and not light. Well they need light I guess, it's just they don't get fed from it. at least that's what I've been told.