well, if you have the money then it might be worth to invest in a core 2 duo lappy than in a centrino, possibly with 1gb ram. also it's nice to have some usb docks to be able to plug in more HDD-s, and an external sound card may come handy aswell (like e-mu 0404 usb). however, all this depends on your vst usage. for example in ni reaktor there's no configuration that you cannot max out easily