Replying to Bike Help

I just started getting into riding dirt jumps and I'm really digging it. I have just a basic Specialized Hardrock. It's nothing special, but it gets the job done.

The one problem I have, is that there is too much extra shit that came with it. So here's what I would like to do:

-The brakes are all coming off and I plan on just using one good brake for the rear.
-Single speed (no fixed-gear hipster bull shit).
-Lighten the frame, if at all possible.

The thing is, I have no idea where to start looking for parts. I've done some pretty in depth searching, but I seem to be getting nowhere. I'm aware that there are different measurements for some parts. I'm just not very familiar with the schematics of my bike.

Any solid info is greatly appreciated. DIY's or places to buy parts...

We all have to start somewhere right? I know someone on here can help me out.