Here's a quite place with a nice view and overpriced drinks.
http://www.10best.com/destinations/...-bar-get-a-sky-high-view-of-bangkoks-skyline/
Below it is the outdoor beer garden area with a lot of food options that I talked about earlier. Noise is reasonable unless stuck next to the band and grabbing a table shouldn't be a problem
I recommend Lubua Towers,
It's epic.
Stayed there for a bit last Nov, didn't ever want to leave that view at the top.
Nice and quiet too.