Why do you need 2 GB of RAM? That first computer looks to be insanely overpowered for mostly anything any normal person would want to use a computer for. My 3-year-old 2600 GHz is quite overpowered for me, and I do things with my computer most people probably would not. Unless you have money you're willing to throw around for not much reason or unless you're doing something massively CPU-intensive or RAM-intensive, I'd say get something less than state-of-the-art and save some money.

Get a really nice monitor, a really nice mouse, and really nice speakers instead would be my advice. Those are the things you USE, things you look at and listen to on a daily basis, and they're things you can take along with you if you ever DO need to replace your computer itself for some reason. 5 nanoseconds vs. 2 nanoseconds to open a Word document isn't something I think anyone should be worried about for example.