Ill just update the thread.
I found weldon number 16 at a local plastics place in a tube and then i ordered weldon number 3 off of ebay. I used the #3 to build the tank then i used the #16 to fill in the small leaks it had. I had a plastics company cut the acryllic for me.
Overall, the entire thing came out good. I built a 60"x15"x15" sump out of one sheet of 1/4" acryllic. It cost about $200 for the acryllic and having them cut it.
It has a refugium on the left, return in the middle, and the skimmer on the right with inlets on both sides of the sump. Pretty similar to this:
http://www.melevsreef.com/acrylics/sumps/f/sump_f.html
So far so good. I'd encourage anyone thinking about building a custom sump to give it a shot. Not as difficult as i thought.