The GTX780 is a very strong card that needs a decent 575w psu as a rule.
The card needs 42a on the +12v rails.
It takes an exceptionally good 500w psu to be able to deliver 42a.
I think you need a stronger psu.
Exactly which one do you have?
The card will fit the motherboard just fine. The card you picked is unusually long, 11.3". The stock GTX780 will be 10.5". Measure the space in your case for length.
It's a shame, but it won't fit... Then again, there are a lot more I can choose from. I was thinking about an Nvidia GTX 750 TI with 2gb GDDR5. I am using my PC for gaming generally. I am playing newest games at High-Very High settings and it works quite well, although the frame rate is at 20-25 fps. What I want is a decent upgrade from my current video card (I suppose you have already seen which one I have).
P.S I am using a Full-HD 1920x1080 monitor