if you are running ADS, 3D graphic card won't make much difference. you need more ram and a fast CPU.

add ram up to 2G, if you are running complex simulation. 7200rpm HD is faster. but top out at 60GB. if you need more space, 5400rpm HD can offer up to 100GB.

right now, 1GB DDR2 SODIMM is cheaper than DDR1. if you want to max the ram, you can save some money with DDR2 notebook.