Bill:
To say I am very impressed is a huge understatement. Very nice progress. I see you mounted the pumps the same way I had in mind to do mine. The only thing, as little as it really is, that I see about the set up so far is that you are going to have to drain the entire skimmer everytime you are to disconnect one of the pumps or any of the plumbing. I am sure you were already planning on putting a drain on the bottom of the box. I have one in my current skimmer and it is well worth the extra effort to get it done.
Also, why are you using 2 drains for it? I presume the 2 bulkheads on the top side of the box is for those right? I would think that 2 would make it more tricky to get it adjusted, but I could be wrong. I would think a single 2" one would do the trick just fine. How much are planning on feeding the skimmer anyway?