I recently built my first gaming rig, It isn't high end but its a decent computer. I currently have my nice 22" Asus monitor and my PC, but my mouse, keyboard and lack of mouse pad is not going to fly much longer. I would prefer less than 150$ but I can work with 200$. I know it may be cheap for certain products but know that I care more about the keyboard and mouse than mouse pad, though I need one so I can stop using a book.
well, my favorite mouse, which is only really criticized for its small size is the Roccat Kone Pure Military. Its also a little on the expensive side at $70.http://www.amazon.com/Roccat-Military-Edition-Performance-ROC-11-713/dp/B00LJZQE8M
the cm storm quickfire rapid is quite a good keyboard for a bargain and gives your more room because it lacks a numpad http://www.amazon.com/Storm-QuickFire-Rapid-Tenkeyless-Mechanical/dp/B0068INSUM $72 for blues, $86 if you want browns.
recommending a mouspad is hard because i like really large ones which wouldn't fit on your desk probably.