I think I've finally got a good idea on how to run the plumbing, but am debating on the location of the OM 4-way. There are 3 options.
Option #1: Put it in the stand. Half of the returns are there anyhow, and the others are the 4 lower returns on the back wall of the tank. The only major con here is it'll take up space in the stand.
Option #2: Put it behind the tank. A reasonable option with the only real con being that there is already quite a lot behind the tank.
Option #3: Put it in the garage. There are only 2 places that it will fit and not get hit by a car door. Over near the fuge setup, or up high above where the car door would hit. The only real con with this idea is running 4 lines back through the wall and to the tank, as opposed to a single line into the house and being split later.
What are your thoughts. I think I know which I'm leaning towards, but don't want to bias any opinions.