What to chose better Snow Leopard or Leopard? I'm thinking about Leopard,but what version would work better? How to install iAtkos v7 from usb?

Specifications of the Netbook:
Processor: Intel Atom N270 @ 1.6ghz
Mainboard: Fujitsu-Siemens Amilo Mini UI 3520 (Chipset: i945GSE)
VGA: Intel GMA 945
Audio: Realtek ALC269
Wireless: Atheros AR5007EG
Ram: 1Gb 677mhz
HDD: Toshiba MK6028GAL ATA 60 GB
Got 8Gb usb.