Thanks Oddmar!
I purposely didn't make my first cast any more complicated than I had to. I figure I'll run this one for a few seasons and after building a few more systems I can tear this one out and improve it.
Thanks for the heads up on those things, I had planned for some of them, but I too had thought only about dropping an 8" cleanout into the side and calling it done, now I know it needs to be a bigger cavity and I'll address that. The plan is to get things rolling this weekend, so I'll try to have some pics up on monday.