well if you look at the specs, laptop 1 is about 1 lb heavier. Honestly 1lb isnt very much expecially if your going to be putting it on your back.
Laptop 1 is on the core duo processor. Its newer in technology hence if you can afford it, id stick with core duo. This is a yonah processor.
Laptop 2 will do the basics without any problem. 1.6ghz dothan is about as fast as a 1.8ghz AMD64. Theres plenty of threads on bench marks about this with yonah, since yonah is technically 2 dolthans put together.
As for battery life, i heard the core duo's have a better battery life then the dolthans. But its not by very much, aprox. 15-20 more min of run time.
Get laptop 1 if you can afford it, as someone stated above me, you should always get the one u can most afford.