New customized computer. :D

So my mom has a friend who can build custom computers for like a tone of less money with like really good components such as Nividia display i5 processors so on and so on. But as of right now i don't know much about getting new components so i need some help.

So if anyone can list some of the components that aren't like too pricy such as i7 processor which i know i won't even need i5 would be good enough.

I want you guys to help me think some of the following
1.Good display card preferably made by Nividia
2.Good cooling system not too awesome like liquid cool etc =.=
3.How much gb of ram i should get?
4.How much Hard drive, one or two. ( My friend has two one has only like 27 gb and it is also his main hard drive, so his computer starts up really fast, but he also has another one with like 1 terra byte of hard drive.)
5.Monitor? since it's desktop
6.How are the system programs like when i put together a program, win7( i don't know how this works)

So if you guys can help that would be great and no bs please. You can also list some of the things i missed putting on the list.