I want to start streaming League of Legends. What PC specifications do I need?

This summer i will buy a new PC for gaming.
My current specifications are:
Pentium(R) Dual-Core CPU
E5400 @ 2.70 GHz
2.70 GHz, 2.00 GB of RAM
Windows XP
I want to stream at 60 FPS on medium graphics. I've tried to stream minecraft but i had like 5 FPS. I currently have 60 FPS in LoL on medium to high graphics, with moments of fps drops.

So, what do i need to stream with 60 fps on medium graphics?

Get a better processor, I currently have a laptop with Intel Core I7 and 8gb ram, 2gb Radeon Graphics and I run 150+ fps ingame

Have a least 8gb or more and have a 2gb graphics card or more

The RAM may be too low, I suggest that you enlarge the RAM for gaming and close apps as many as possible when playing games.

You really don't need a good graphics card. I used to have Intel HD 4000 (it's very weak and integrated) and the game ran at 60 FPS. This game only needs a GOOD processor and a nice amount of ram.
Get at least 4 GB of Ram and an i7 3770k processor.