Flash Memory Speed Rating Need Information On A Laptop's Memory?

Need information on a laptop's memory? - flash memory speed rating

I'm going to buy a laptop, and I saw an eMachines laptop. I know nothing, the team connected, but that's what the website says:
2GB PC2 @ 667 MHz DDR2 memory
SATA 160 GB hard drive, rated speed of 5400 rpm

It is a 4 GB USB flash drive possess, too.

Is that enough storage for iTunes and Microsoft Office? I do not think about installing games ... Just surf the Internet, download music and writing paper.

Thank you!