are you planning on heavy use of the wireless network? i find that when transferring files between my two pc's here at home even with only one on the wireless, it's much quicker just to plug it in to the cable..
Yes, most peoiple have 54 Mbps wireless, and everyone has 100 Mbps wired

(even if your wireless were running at full speed, which it rarely does e.g. if you have a microwave in the house, or a cordless phone, etc etc).
Wireless networking in home and office == one of the most stupid ideas ever.