Wireless Recommendations
 

Right now I'm using a Linksys WRT54G 54Mbps Wireless Router connected (via 10/100 Cat5 Cable) to my 700MHz Athlon and (via 11/54Mbps Wireless) a MacBook. I got everything working fine, but the router is a loaner only till July. So I need to know what'd be a good 54Mbps setup for the following:
--eMachine 700MHz Athlon PC (it'll be connected wirelessly @ 54Mbps)
--A new Athlon X2 3800+ (connected wired, preferably via Gigabit ethernet, but I'll gladly accept 10/100 as well), which I'll be getting real soon (for real this time, I've been saying this since 2003:))

What I want is to get a great wireless router and PCI wireless card for my old eMachine PC. $100 is my limit, so try to keep things cheap.

I think you're stuck with getting a linksys WRT54G then. Those gigabit routers and switches starting price is usually over 200 dollars ._.
Besides, the above mentioned router is probably easy to find in your area. I'd say Walmart has them at a decent price (under 70 dollars I think.)

Edit: Nevermind what I said about 200 dollar switches. Apparently newegg has one for under a hundred dollars. Though, its not wireless capable and I'm not sure how reliable it is.

Okay, that means a $50 purchase (at least from Best Buy). Now, I'll I need is a wireless card and I'll be set.

How powerful does a wireless adapter need to be to connect to a router two floors down? At the moment I have a Mac up in my room which can connect to our Airport in the basement, but I'm considering getting a wireless card so I can move my PC up there.

For compatibility sake I would stick with linksys. If not, at least look for the wifi certified sticker (see below) when buying a wireless card.

http://img.photobucket.com/albums/v6..._certified.jpg

Any standard wireless card should be able to transmit well enough for web browsing through two floors. I wouldn't try to play online games through it though.
But if you have the extra cash, getting a high-gain (indoor) omni-directional antenna for your access point will definitely help.