To both questions:
I've played GWX 1,03 on a 1,4 GHZ AMD, albeit with 1gb Ram and a far heavier GFX card, ati x850x pro
still, both of you should be able to play, and never used light harbor traffic, possibly add some memory though, and I suggest being careful with the museum, be sure to restart your game after visiting it's rather memory heavy I've found
now go forth and sink them!