I want to make a system upgrade in few days because my system has got old !

Here is my system!

Mobo : Gigabyte Gmx-s2 (very slow and old)
Processor: Intel Quad Core Q6600
RAM: 2 Gb 667mhz
HDD: 500+500 Gb HDD 7200rpm
GFX: Asus 8600gt Passive gddr3
PSU: an ordinary 420 Watt just to run(it makes so much noise that i want to break it)
Tower: an ordinary tower with bad airflow


here is the system that i want to build!

Tower: Antec Mini P180 White Case ______ 45 Euros
Mobo: DFI Lanparty DK P45-T2RS + ______80 Euros
GFX: Ati 4870 XFX HD-487A-YDF SVGA ________ 129 Euros
HDD: no new necessary
Processor : no new necessary
RAM : OCZ Nvidia Sli 2GB DDR2-1066 Ram Kit (PC2-8500, 5-5-5-15, OCZ2N1066SR2GK) _______ 23 Euros

and i do not know which PSU to choose :
i have selected 3

1. http://www.plaisio.gr/product.aspx?p...amp;catalog=20
2. http://www.plaisio.gr/product.aspx?p...amp;catalog=20
3. http://www.plaisio.gr/product.aspx?p...705&page=1

which of these 3 is the best?

Please tell me if this upgrade is good and worth buying!

Thanks in advance!