Finally got enough elbow fittings in to take a crack at how I've envisioned Loop V1 (there's almost aways a V2 shortly after the first...

). I'm using flex tubing, but the idea is to use straight runs and fittings/extensions if it was rigid tubing. Pictured above is the temp air cooled version. The PA can go back in the box for a future build.
I've already got a pic up of the return line from the rad to the pump, this was the first roughed in pump outlet going to the cpu block. I know I won't be able to get everything to match up exactly, but this looks like it's going to be a decent fit.
Here's the final (dry) loop. The lower line requires some kind of support, but I'm not really happy with how the dual cable clamps turned out. I suspect I'm going to try to print up a brace for a single cable clamp on the side that attaches to one of the bottom mounts of the pump.
Not quite as straight as I'd like, but close enough that I don't think OCD will kick in every time I look at it.
2.5 hours into the leak test without any issues. Loop is pretty much bled and I'm not seeing/hearing any trapped air.