Looking for do's and do not's.

The wife has decided that we need to ad a fireplace next to the sitting area in front of my recent water wall build.

Since I've never built a fireplace before I've decided that getting some do's and do not's, (while the heart cures), would be a good idea.
30 60 lbs bags of concrete went into the 5 inch lid on the heart. It's reinforced with re-bar and an angle iron for good measure.
Currently, while it's being watered for 3 days, I am scratching my head on how to accomplish the throat??
Not looking to buy a kit, rather use firebricks, cinder blocks and perhaps a few sections of flute.

In the process of finding a place to buy fire bricks in Seattle.


Water wall video for those who are interested:

1.Untitled on Vimeo
2.Untitled on Vimeo