The best "router" I have encountered for consumer class wireless networking is the Linksys WRT54G or GS (although I dont reccomend trying to use SpeedBooster). The worst might be the Belkins or the BEFW11S4.
As for client cards, any Prism or Hermes (ORiNOCO) based card should work for 11b... Broadcom cards are ok hardware wise, but the drivers for Windows are pretty shabby. The Prism 2 GT is reccomended for 11g access although I havent tested this yet.
The table here shows many cards and their chipsets:
Personally I have the follwing cards that work well:
alvarion BreezeNET PC-DS.11b (its a rebranded Lucent/Avaya ORiNOCO Gold)
D-Link DWL-122 (Prism 2.x... its a small USB device)
SMC SMC2532W-B High Power Wireless PC Card (Prism 2.5, card has a 200mW xmit output, but recieve is about the same as the ORiNOCO)