I am shopping for a laptop. I think I will get an IBM X40. However,
this laptop comes with any one of eight processors. I've listed some
below:

Ultra Low Voltage IntelŪ PentiumŪ M Processor 1.00GHz
IntelŪ PentiumŪ M Processor 713 Ultra Low Voltage 1.10GHz
Low Voltage IntelŪ PentiumŪ M Processor 1.20GHz
IntelŪ PentiumŪ M Processor 738 Low Voltage 1.40GHz
IntelŪ PentiumŪ M Processor Low Voltage 1.20GHz
IntelŪ PentiumŪ M Processor 1.70GHz

Help, what is the difference?? I don't know much about processors, but
I thought I heard that the raw value of "GHz" does not necessarily
equate to faster/better performance. I will primarily be using the
computer for MS Office apps and internet/email (no games, multi-media
editing...). I don't need a lot of performance, but my current PC runs
like molasses so I want a fast, seamless feel.

How do I make out the difference between these options? What might be
best for me? What is the relationship between things like clockspeed
and L2 cache and performance/speed?

I was planning on getting 512mb RAM, 40g HD.