external or internal wireless?

I am going to be needing a wireless card/usb router.
I'm going to be feeding off, my dad's Linksys' cable feed.
Wondering if there was a difference between an internal wireless card, or getting a usb based one, other than the obvious.
What do you recommend?
Got my eye on D-links G132 model. (for the external)
http://www.dlink.com/products/?sec=0&pid=358
Since I've been working on them a lot lately in terms of helping friends and setting up their wireless home networks.
Thanks.