I have

Intel DG41WV Motherboard
Intel Core2 Duo E7500 2.93 GHz CPU
NVIDIA Geforce 8400 GS 1GB DDR3 Display Card
4 GB RAM
500 GB WD Hard Disk
PCI Firewire Card

Please suggest which Snow Leopard OS X should i go for... I have never tried installing OSX before, This will be my first time...