Right, it's a bit complicated. Best if I take each separately. You have the Corsair H5O, H6O, and the Antec Kuhler H2O-620 as all-in-one watercooling solutions that have a 1" thick radiator. You then have the Corsair H7O, H8O, and the Antec Kuhler H2O-920 as the solutions with the 2" thick radiator. All the pump/CPU blocks should clear the 300/450W PSU fine, and don't seem to interfere with board components in my experience.
All the radiators can be mounted in three different ways.
a) With the rad mounted horizontally in the front of the case. This will allow you to mount an optical drive in the front (you will need to dremel off the HDD bracket) but it will stray into the space for the graphics card, and you will lose the equivalent length of the rad - as you can get away with a total of 10.25" in the SG05, mounting a rad this way will leave you with either 9.25" or 8.25" depending on your choice.
b) Mount the rad vertically. This doesn't interfere with the graphics card choice (you get the full 10.25") but you won't be able to fit an optical drive - the bracket that holds it will NOT fit in the case with this method.
c) Drill holes yourself to mount the rad slightly off-centre. This allows you to get away with both an optical drive and the full 10.25" of graphics card, but it means you will have to drill your lovely new case.
Note that mounting the rad lower by drilling may also affect your ability to mount the HDD to the bottom of the case, as the rad will foul that idea. So you'll need to improvise it somewhere else.