i'm thinking about getting an airport base station and 2 AE cards for my home. i have a PB and an iMac. i connect to the internet via dial up. do i have to have the AE BS w/ the modem port, or is that just to allow me to dial in from outside the house? or to surf on the PB w/o having a phone cord attached, do i have to have the AE BS w/ modem? thanks.