I've looked for bags at Arlington Camera before but never found one I wanted, probably because there were too many choices. While all my bags are black Lowepros, I suggest buying the rattiest looking Hello Kitty backpack from Target and hiding some foam inserts in it for your gear. Go stealth!
My bags have all been bought online from
B&H. Its selection is even better, but you have to feel comfortable reading descriptions, reviews and such without ever touching one. I contacted customer service one time to see if my laptop would fit in the sleeve of a bag (said 12-inch and mines 13). About two minutes later, they confirmed that it would.
EDIT: I went to high school in Wylie, and man has it changed since then. It's almost time for that place to have a camera store (almost).