Dude your 200 is unrealistic....go to newegg.com and look at case prices ,power supplies ,a dvd burner,video card etc. you will have an idea how much it will take..cheapest systems ive built latley have been amd and been in the ball park of 350 to put together a respectable system...a board with on board graphics like the 785 series would be fine for you...these systems are athlon 2 .....if your not in a hurry and watch combo deals and sales you might beat 350 a little bit but ill tell you one thing a rig for 350 are very quick for internet use and running programs...there quite impressive and ive been building computers since 1996...they still amaze me...you can build a very good quality system yourself much better than buying a dell or hp or something..plus youve put it together yourself and did all the quality things like running wires nicely and having a professional look to it...buy an inexpensive window case and you can enjoy your work and amaze your friends...you have a conversation piece in the room...
good luck and go to newegg ,mwave ,zipzoomfly ,directron ,superbiiz ,and look at prices for the components you need then you can get help on choosing a mobo ,cpu and ram...you can also price out intel stuff too but your gonna find either one you choose for the kind of use your talking about you will see no difference with either brand .....good hunting dude..........................