Well I own a mechanical keyboard, the XArmor U9BL, and I'll never go back to rubber dome. To find out all about mechanical keyboards read this guide:http://www.overclock.net/keyboards/491752-mechanical-keyboard-guide.html
As for mice, the Razer Lachesis 5600 is actually quite bad. Stick with either the Razer Deathadder, or a mouse the A9500 sensor. Mice that use the A9500 sensor are the Logitech G500/700, G9X, Steel Series Xia, Roccat Kone+ (my mouse) and some others.
To recommend you a mouse, I did to know what your grip is, palm or claw.