Very nice pics of your project so far. I could probably help in the plumbing dept. when your ready. I agree with most of what CL said, although the only reason I have ball valves on my system is to shut the water off, not to slow flow going into the sump, I just use filter socks to clear up the micro-bubble problem. I don't believe in restricting the drains at all. Just remember the drain hole sizes is what you have to work with as far as flow, then you need to figure head height, friction loss from elbows, T's, etc. when determining your pump, I would try to get something that doesn't need cut back by a valve(just wasting electricity and adding unwanted heat possibly). No need for check valves, they will fail, although they may work a little better for you, since the sump is in the basement. Another good thing about the basement sump set-up, is if there is a problem the mess can find its way to the drain in the floor( I hope there is one). All that is needed for preventing back siphoning is siphon breaks in the return line(these do need checked for clogging, especially if made too small, but do the job perfectly. I won't get into everything now, let me know if I can help when it is time. Good luck, looks awesome so far, I'm jealous. I need to convince my wife a nice 8'Long X 4'D(front to back) X 2'High tank upgrade for my addiction.
Matt