I brought a ViewSonic 24" Wide LCD Full HD VX2439WM (with HDMI) nothing fancy and good enough for gaming and watching dvds cost me $300. For a mouse and keyboard any cheapo will do I use a Atec Laser mouse that comes with all these extra buttons on the side/tops for gaming that I never bothered to setup and configure since owning it. The Atec wasn't cheap though.
I wouldn't mind getting this mouse
Cyborg R.A.T 9 Gaming Mouse 