Trying to setup a GPU mining rig.

[Frenkz]

Hello everybody, I've been struggling for days trying to find a good setup for GPU mining rigs. I'd like to have some help. I'm trying to pay the cheapest for maximum possible hashrate!

Things to know :
-I live in canada
-1300$ budget (Lower if possible)
-Don't suggest me to don't mine (please)

I'd like to run either a dual/triple GPU depending on what's available, for the moment the best GPU I've spotted would be this :
 MSI Radeon HD 7950 3GB GDDR5 (Twin Frozr)   (Would run around 690 kh per GPU) at roughly 370$

Anyone got better ideas? I've been looking around a lot and most of the popular GPU cards are B/O =/!

[gamefixer]

What are you trying to mine?