using the Silverstone SFX-L 500W, The space from the top of PSU to bottom of graphics card is 2.5cm or 25mm,
cable plug-in connectors from the bottom of PSU & up are 1.5cm or 15mm, So leaving 1cm or 10mm free of space for cable/wire
you could mod the case Doing away with the black PSU mount bracket that takes some hight on the bottom front of the case & just use the SFX PSU flat adaptor plate in place of it,
2 ways of doing this,
1) would mean making a hole in bottom rear case panel & bottom panel for the AC power cable to pass through inside the case & under
or
2) you could just have the AC power cable dangling under the case without making any holes for the AC power cable to pass from inside the case.
I say dangling you could use a cable tie in 2 of the holes where the 2.5 HDD/SSD mount holes are.
I am going to do this, will post pictures soon, Corbin Dallas!
flipped on its head, I did try this when I started the project, Changing the motherboard-tray & panels so the window side on my left & Graphics card at the bottom when sitting on the bench ,
but there few incompatibility with power bottom, black mounting tray on bottom & screw holes,
but possible if modded, be really no temperature difference.