bharms :
What do you mean by a fast wireless card? Do you simply mean going for wireless N, or do you mean that cards in the same category (b, g, or n) but by different manufacturers will have different performance? If the latter, who makes the best cards?
Wow, I've not been on here in a while..lol Some cards use better chipsets than others. There are standards that rate the chipsets in different categories, such as sensitivity, power consumption, output strength, etc...
that is why some cards are $20.00 and other are an upwards of $70 - $100. Better performance from different angles, distances, less prone to random disconnects, not phased by interference as bad... the list goes on. Shop with caution, but most of the time one gets what they pay for.