By all means have a meal on top of the State Tower. Mezzaluna is wonderful, as is Flutes, the champagne bar on the roof. I haven't ate at Sirocco, which is outside along with Flutes, but have hear good things about it as well.
Here's an overview of the dome restaurants. I know they each have their own website, but I can't seem to find them at the moment.
http://www.thedomebkk.com/abtus.html

Do searches on each of the restaurants and I think you'll find lots of good reviews. IME, it was one of those rare experience where the food matched the views. Prices are high by BKK standards though.