What is the cheapest good quality mobo that retains upgradability?

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1

 this was my ideal build for around 1200. http://pcpartpicker.com/p/BQhK

But since im still not sure how much im going to have for budget i think 500 dollars will leave me room to buy an upgradable build. I was trying to see what is the best bang for my buck mobo that will support an fx-8350, 32gb of ram and a 7970 later on. On that note will 550w psu have enough power for an fx 8350 and a 7970?

2

550w should be fine although I would spend extra on a 600-650w especially with the 8350 if your planning on overclocking it.

3

Id go for the Gen 3 Sabertooth boards, as they have the most up to date features that other chipsets will more than likely have.

4

How can i tell if they are gen3 boards?