Absolutely, the only thing you need to be careful about is the graphics card. Any processor they sell will be sufficient, however if it's shared/onboard graphics it most likely will not be. The 2 choices you have, both will be sufficient, in order of power: the Radeon Mobility 9000 (M9), & the Geforce 4go (G4G.) I recommend the M9. You MIGHT have better compatibility with certain graphics plugins on the G4G, but it's not really a Geforce 4, it's a Geforce 4 MX, which is basically an overclocked Geforce 2, which = crap. The M9 is an excellent card, and it's equivilent to the desktop Radeon 9000 card, with it's speed somewhere inbetween the regular 9000 and 9000 pro. It's also got pixel/vertex shaders and full DirectX 8.1 support, unlike the G4G. Those are basically the only two options you will find, other than onboard intel. The Geforce 2go would be a sufficient but very low-end for N64 emulation, however I don't think they sell it with new machines anymore, it would make a good "value" card for laptops, but they use the onboard intels for that.
I have a P3, 900mhz, with an M9 and get 100% speed most of the time and at least 75% speed the rest of the time with N64 emulation, and breathtaking & perfect graphics with most plugins (some plugins have problems with Radeon cards due to the garbage drivers they produce for them, but it's gotten alot better lately.)
(The plugins supporting Radeons has gotten better not the drivers themselves, although I do think they have gotten marginally better, although I suspect things will change soon on that front.)
