Wireless card question?

The router uses the IEEE 802.11g and 802.11b standards which run at 2.4GHz. A higher frequency card will work with your router, as long as the card supports the 802.11g standard, but it will run at 2.4GHz. The only way to have a card run at a higher frequency would be to buy a router that supports the same frequency- such as one running the 802.11n standard which operates at 5GHz.

That being said, I wouldn't worry too much about your router and phone interfering with one another because you can always change the chanel that they use. It's best to leave your router and wireless card set to channel 6 (most manufacturers use that as their default). If you notice that your network connection drops when the phone is being used, then just change the channel on your phone.

11n if you can afford it, the old pre-mass-adoption 11a also works at 5 GHz, it has shorter range so might no good for your use.

PCI vs. USB no difference I prefer USB better. Though USB take more power.

I have doubt the channel change could work, I did not have trouble using an 11b bought US in Taiwan without channel change, US is ch. 11 Taiwan is ch. 10 according to what I read later the biggest frequency gap between channels were around 10 MHz.