1. yeah they will all work together
2. Depends on the games you play and what your monitor's resolution is
3. Gigabyte makes quality boards
4. It depends on if you overclock and if you plan on running SLI/Crossfire with your graphics cards in the future
5. Again it depends on the games you play and the native resolution of your monitor
If you are in the US and have access to newegg there is a REALLY good deal I just got in an email for a budget deal. It comes to $139.97 after Mail in rebates.
But im not sure how long it lasts for It may be only today but if you are interested i could forward you the email just let me know. It is pretty close to everything but its a dual core processor instead of the quad so it wont be "as" powerful but close to that and for a price for A cpu, mobo, ram, and GPU for less than just your CPU.