I want to get the 5850 for it's good price/performance but it's out of stock on NewEgg and don't know if it will come back.
So far, I've picked out the Razer Black Widow and the R.A.T. 5. I originally was leaning towards the deathadder but I heard that it has many problems. I really want a mechanical keyboard so the Black Widow seems as a good choice.
First things first. Any wired keyboard and mouse will allow you to game. How about putting that $100 into your computer budget where it can go towards performance? This will allow for a Core i5-2500k and a P67 motherboard. Here's a comparison from AnandTech that will hopefully change your mind. http://www.anandtech.com/bench/Product/288?vs=88
I get that you want a nice keyboard and mouse for gaming...I really do. But it shouldn't be 15% of your budget. Get the above parts and go to Wal-Mart for a cheap keyboard and mouse until you can save up to get the nice ones you want.