All-In-One Home Server

[x_rufus_x]

Hello Guys,
I need some help here.

First of all, sorry for my bad english, it's not my mother tongue

I'd like to build an All in One home server, I'm a beginner on virtualization and I had a lot of doubts

The purpose of the Server:
1) Backup. I have 500GB of data from 3 computers on my home that I'd like to store as backup on a Virtual Server.
2) TorrentBox (WinServer 2008?). I'd like to have another machine as torrent box 24/7.
3) Storage + Home Network share (FreeNAS?). I have another 1TB of data (movies, music and tvshows) that I'd like to share to my home network/ (2 x windows 7 and 1 x macbook)
4) Study. I'd like to have some linux machines to make some development experinments.

What I already have:
Processor: Intel Core i7-3770 Quad-Core Processor 3.4 GHz 4 Core LGA 1155 - BX80637I73770
SSD: OCZ Vertex 4 120GB
HD: 2 x 2TB Caviar Black and 1 x 2TB Samsung
RAM: 4x2GB

I've read some sutff and I know that 8GB is not enough. But until I'm confort with this solution, I'd like to play a little bit with this config then upgrade to something better (32GB maybe??). I dont know if I can build something with NFS storage. I don't have much money to spare on a RAID controller (If i'm not wrong, I can't do it through on-board raid).

So, with what I have, which options I have to build an ESXi with those spec (Hardware+Software) that I listed above?

Thanks in advance