I did a lot of research on this not too long ago as I was trying to squeeze out every possible advantage to make myself more competitive so I could contribute more during scrims.
I put this question to my Reddit Clanmates and I can't think of one who is not using a mechanical keyboard?
There's so much on this topic that it's confusing to say the least as most of it comes down to personal preference. I don't think many would argue that wired is faster than wireless as there is a difference in input lag. I also think batteries is just not a feasible alternative for heavy usage on any keyboard and since I use mine for much more than just gaming, wired is the only way to go.
After talking with a lot of comp players using all manner of hardware, I settled on the Max Nighthawk X8 Cherry Brown. The brown switches are perfect for me as there still tactile however activate with a pretty light touch and are not as loud as a black for instance.
Here is a decent guide to help you understand the differences in mechanical keyboards:
http://www.overclock.net/t/491752/mechanical-keyboard-guide#post_6009418
As for mice, I selected the Logitech G500 because it's just awesome, period! You can switch DPI on the fly, the thumb buttons are nicely placed and the weights are a very nice touch. I have medium weight inside my mouse which makes it a bit heavier but is a great match for my mouse pad.
...and yes, do yourself a favor and get a mouse pad.
I'd pick 2 real cheap pads to begin with, one fabric and one rigid and see which works best. You do not want to pick the one you like better because it's doing you a disservice to say the least.
I used the fabric mouse pad for the longest time because the rigid pad would sometimes allow the mouse to slide on its own as the surface is so slippery. This was the biggest mistake I ever made.
The fabric mouse pad although accurate, actually makes twitch in small increments bl00dy impossible. I switched to the rigid mouse pad and hated it the first week, got used to it the second and will absolutely never go back.
I can say for a fact that this combination has made me much better in Battlefield 3 which is what this setup is designed to do.
In my case though, everything I picked was for a reason and all designed to work within my specific needs; yours may be different.
For example I could have chosen any backlit keyboard but went with the Max as it was blue backlit which matches the lighting in my case. I know it's a little thing but it was aesthetically important to me that if I'm going to spend the money, I want everything to look consistent.
It may be silly but if it adds even a minuscule amount of psychological comfort perhaps it helps me perform just that tiny fraction better.
I picked the mouse for a few reasons, one being I love Logitech and have had nothing but positive experiences with both their hardware and Tech Support and it fits my hand the best.