I have a few doubts on some of this - though I applaud ambition!
I have one of the Silverstone SFF PSU units and it is not an easy marriage with the Cube. Issue is that while it may fit it has an air path which has a 90 degree bend in it, so wherever you exhaust the air, you need a free air path at right angles to it. In a Cube that is not possible without cutting out one of the acrylic sides of the case (and the metal). Another issue is that even if you get it to fit in the Cube you will not have room for the rest of your components.
In my opinion if you want to keep it all in the cube and not cut the exterior then the only sensible way for powering is to keep consumption (total watts) down to what can be provided by either the largest PicoPsu, or to find another PSU with a possible straight line cooling path preferably bottom to top that will physically conform to the constraints of the cube enclosure. Or to find a decent Thin ITX or other format option that will satisfy your needs.
Just as a heads up on my next cube the mechanism I plan on refining is a strong magnetic catch to keep everything in place.
By the way the two bolts thing at the top (your option 3) is what I used in my water cooled cube and that is a reasonable (and safe!) way for securing the core.
Thanks minihack!
In fact, I agree totally with you!
The fan on the ST45SF-G, 90 degrees from the intake, makes it complicated.
I like the SFF of this PSU, and that it gives you 450W (I have the 160 pico-PSU (200w max) too, but it just doesn't put enough power for the 6-core.
I'm at home already(Buenos Aires), with all the parts I brought from USA yesterday, so this weekend, I'll try to start putting togheter, at least in a mock-up cube case made with MDF to start checking checking temps (and to see if everything works or if there is something DoA)
Regarding the 90 degrees on the Silverstone PSU, I've been thinking (and dreaming) about it.
I've thought into 2 extra options besides the hot air going to the center, and then to the top exhaust (which is option 1):
Option 2: (preferred)
make the exhaust (90 degrees from the intake), to blow the hot air, not to the center of the cube, but to a side of it (a small gap), that will lead the air to the top of the cube (to the gap of the DVD unit). It should create a flow from the intake at the bottom of the Cube, to the top DVD Gap(removing the felt of course).
Or, if I set the mobo at the front of the cube, the PSU will be at the place where everybody puts the mobo, and then it will have the gap on top (the venting of the original cube's graphic card)
Option 3: (this involves stripping the PSU)
By looking at the officials photos like the following, I've started thinking on changing the orientation of the stock fan, so it puts the hot air 180degrees from the intake at the bottom. Or possibly changing it for a smaller one. (I don't like to remove it for safety hazards, because If I do so, I'll need to replace it with a resistor and I don't want to go that path yet.
All the above, is going to be difficult if I use the stock cooler of the ASRock X99E-ITX/ac, which is:
Dyantron's R24:
But I've also bought 2 alternatives for the 140W TDP of the i7-5280K, with much lower profile like Dynatron R25 and R31:
Dyantron's R25:
Dyantron's R31:
Please note that these 2 are server type coolers, so they need a constant airflow that goes through the middle of the many many fins they have. I bought also a couple of Noctua low profile coolers for this purpose, that paired with a 3d-printed plastic air tunnel would make the cool air go from the bottom, thru the R31/R25, and then up to the exhaust open in the top of the cube.
The above smaller coolers will make the blue square (R24) much smaller, easing the airflow along the core of the system.
But I'm not done, on the thinking I've put to this:
The above 2 options, if I go the regular way...
I've been thinking really outside the cube in case my preferred approach (air going from bottom up only) doesn't work.
This involves, as you say, holes in the acrylic and metal on the back:
The idea is that the 90 degrees will go to the back of the cube. This will allow, perhaps, a direct connection from the video card to the mobo (it may go down more than the bottom. I need to check this)
OK, now I'm done.
Let's hope I have some positive feedback when I'm done with all my temp testing in the mock case I planned to do this weekend.