Hi Jim,
Wow, must be nice with the pvc bender! I am actually using a butt load of 45s so as not to lose too much flow. I'm going 1" up to the tank for the return and then switching over to 3/4" at the outlet. For the CL I'm plumbing it literally at the top of the tank right outside, so it's 3/4 the whole way with flex pvc incorporated for vibration buffer. Since it's right at the tank I can literally just yank it off, no TUVB required

And, I'm just using unions for the return as it drains out into the sump when unplugged so no leak worries. This is my 3rd plumbing project, so I'm hoping for less mishaps! I've actually decided not to drill on this one- have the space for the overflow and we all know that bulkheads can leak. And, that what can happen will, eventually, happen.
Yep, got the 20g still. Will rip it down once all fish additions have been made to the new one (I'll use the 20 for quarantines.)
I've decided to make the new tank an anemone + sea grass lagoon with dsb.

I'll probably throw a other things in, but am going sans calcium demanding organisms this time as I only plan to add calcium via water changes and kalk in the top off.
Can't wait to see your plumbing! But, you're idea will have me use locline again for the non penductor outlet. I'm hoping having the one outlet mobile will help get the flow where it needs to be. We shall see, cross your fingers for me. I'm still a little undecided on the both on one side or on opposite sides thing. Was kind of hoping Gary would chime back in, but probably I'll just post it up in the discussion forum where I'll be forced to bump it up 50 times to get an answer:/ Anywho... :O)
-A