Which slot do I put my GPU in?

So i am going to build a PC with this


Corsair Obsidian 750D

Intel Core i5 4670K haswell

Sapphire Toxic R9 280x

AsRock Fatl1ty Z87 Killer Motherboard

XFX 750w 80+ Gold Fully modular

1TB 7200RPM Seagate Barracuda HDD

G.skill Trident 8GB 2x4 2400mhz 165v

Rosewill Wifi adapter

2 Corsair AF120's RED LED fans

Some Red LED light strips

DVD drive

Do I put the GPU in the top or bottom because which ever is better for airflow and easier to reach for cable managing. It has 3 GPU slots (PCI) do i put it lower or up? If i put it in the first one, will the heat rise up quicker so that it doesnt stay in too long? GPU is a Sapphire
Toxic R9 280x. Thanks!

PS: Do i put the ram in the BLACK or red slots?
 


Oh ok but its still like even if it wasnt default, its still better right?

What do i benefit from it being up there?
 


May i ask why your profile pic is hammer? Its nice! It really stands out! xD

Also, you should be a moderator.
 
As I read this 3 x PCI Express 3.0 x16 Slots (PCIE2/PCIE5/PCIE7: single at x16 (PCIE2); dual at x8 (PCIE2) / x8 (PCIE5); triple at x8 (PCIE2) / x4 (PCIE5) / x4 (PCIE7))
Any slot single card X16
Dual SLOT 2 and 5 X8 X8
Triple SLOT 2 X8, Slot 5 X4, SLOT 7 X4
So really it does not matter with single card.

Hammer was brought in because Tom's lost it for a while before they brought it back. If you could zoom in you would see the Toms hardware on the handle. Sits in my tool drawer.
Was offered but turned down the Mod position couple of years ago.
 


Turning down mod? Boss! XD



So if it doesnt matter, which is best for cooling options if i have 2 front Intakes, 2 top exhaust, One back exhaust. And the Top front intake will have no HDD cage blocking it. So whats better? Might just use the first one though
 

before i give u solution, random question. AMD or nvidia?