I finished getting the bilge built up under the center fuel tank.  Thanks to the advise of Gerry and some other contacts, it came out as I had hoped.  Now to build mock up fuel tanks out of cardboard to be built. (more on that later).

I ended up using 2 gallons of 105 epoxy with 2 cans of the extra slow hardener.  Then about 8 lbs of sand.  It mixed up to about 6 gallons.(in 2 separate batches.)  I used 8 feet of deck board as well as filler in the epoxy.  

1.   Put a thin, 1" layer of epoxy/Sand mix in the bottom and spread it around.
2.  Added my cinder block, wrapped with wax paper to the center area where the bilge pump will be.
3.  Added my deck boards.
4.  Added the rest of the first batch of mix.
5.  Mixed up second batch, added more deck board and poured it in.
6.  On top of this I laid a 1" diameter pipe wrapped with wax paper to make a channel to the bilge area.

7.  Waited....noticed my deck boards were slowly floating up. So I took some long steel pipes and wrapped the ends with wax paper and used them to anchor the boards.  I have 3 holes I will fill later.  (Chance of rain...will wait for better weather).
8.  Note to self.  When your slow cure epoxy is curing...do NOT do things like sand above the area.  I dropped a few bits of stuff on top of the epoxy.  
9.  Also my mix looks white.  There is a thin layer of bubbles that rose up in the epoxy.  Probably 1/4 of an inch.  In a few areas they popped and a darker look is present.   I will paint on a layer of epoxy to fill any small holes.

 Here are some pictures of what happened. 
 
 .  In a few areas they popped and a darker look is present.

Here are a few pictures:

     
 You can see the channel from the pipe.  My boat is not perfectly level currently.  I was worried about my epoxy creating a non level floor and trapping water.  This will help all water find it's way to the pump out box...Still a little cleaning up to do.