Last one I helped set up, we ran a second wireless hub back near where the desktop sits (rather than the one where the XBox360 sits). More flexibilty when it comes to expansion and whatnot, depending on equipment, of course.
Word to the wise -- just because a Linksys wireless router looks the same, and has the same model #, save for .00000000001 difference in version, it doesn't mean they'll connect. I'm glad I wasn't the poor sap who spent hours waiting on tech support to share that info, but if you're trying to link multiple Linksys routers, they need to be the exact same, or the older models did, anyway.
I'd get PCI cards. Go to your nearest Best Buy and they'll have everything Linksys. Also, you can pick up a cheap wireless extender if you have multiple floors or a large house. Doing wireless Bridging isn't a bad idea if you have two PC areas where you have multiple PCs. Lets say you have a Library with two PCs and maybe another PC in the next room and then you have your bedroom or office where you might have a network printer and two computers for gaming or something, you could set up two seperate wired areas and connect them using a wireless Bridge, however, just beware that you might run into problems using the two wireless Bridge APs as wireless APs as well.