Since I always have an itch to build new systems (when my wallet agrees 
) I was looking at the ThermalTake Tower 300.
What I find interesting is that there could be potential for good airflow and thermals if you lay it on the side.
You could set the top & bottom fans (i.e. now left and right) to intake fans, and use a 420mm AIO as exhaust in the back. The graphic card pulls in cool air from the front.
You could possibly jury-rig a larger fan at the right side (formerly known as bottom of the case), to suck in more air.
I have not had hands on with the case, but I do not think there is room to do a push-pull configuration on the AIO. Which would have been nice.
Any thoughts or experience with this?
Also by having it on the side, you most likely will avoid air bubbles in the AIO to get into the tubes opposed to when it is upright.
Edit: adding 2 140mm fans to the back plate as exhaust should also help sucking out the hot air.
NB: Picture courtesy from ThermalTakes homepage, i added the arrows (in case you’re wondering 
).