Update time. Man, cramming water cooling into this thing is a tough task. I ran into some dimension issues and some tubing issues as well.
Let's start with how it sits today:
Notice the lack of fans on the top radiator? Well, there is a bit of a spacing issue with the GPU block fittings. The standard EK XT radiator is just a tiny bit too thick for fans to be mounted in a push configuration. I have a Magicool Slim 240 in my Caselabs M8, and I'll be swapping that at a later date, and then I won't have an issue.
Spacing in general is really really tight in this case, even though it is "massive" for a Mini-ITX case. After attempting to fit things based on my rough estimates, I'm back at FrozenCPU to buy more junk to make things fit nicely.
My final loop, which I feel very confident about is this:
(This is direction of flow perspective starting from the CPU block/pump)
CPU block/pump
45 degree rotary
90 degree barb
20mm extender
GPU block
40mm extender
90 degree barb
90 degree barb
25mm extender
Top radiator
20mm extender
30 degree rotary adapter
standard barb
standard barb
30 degree rotary adapter
90 degree rotary adapter
Bottom Rad
90 degree rotary adapter
dual male coupler
90 degree rotary adapter
Reservoir
90 degree barb
90 degree barb
CPU Block/pump
The tube runs are mostly tiny and it should turn out to be a really slick build when it all put together.
Now about the tubing issues. I snagged some 3/8 ID, 5/8 OD tubing for this build, to save a little space on the inside. This turned out to be a mistake. The tubing is incredibly stiff and seems like the ID is slightly less than 3/8"
It was incredibly difficult to get on the barbs, and absolutely impossible to get off. To remove it I had to grab a really sharp pair of scissors and cut the tubing off as close to the barb as possible. Unscrew the barb, and then cut the tubing off of the barb. So I snagged some 3/8" ID 1/2" OD, hoping that it will be much more supple and easier to deal with. Since my tube runs are going to be mostly straight (thanks to all those fittings and extenders), I won't have to worry about kinks.