M.M.
I have always found the options online lacking--usually all of the Tech online sources are out of stock or overpriced. It's also frustrating because the sizes are usually jacked up--I know I ordered a 12-18 month onesie once and luckily thought to try it on my 3 month old...it fit!
From what I hear, Red Raider Outfitter is opening a co-op store at Mockingbird Station...they'll have a booth there with other universities. Could be helpful, even if it's a drive.
You won't believe the Tech baby stuff you'll find at the Sam Moon luggage store--caps, booties, socks, pacifiers, sippy cups, etc...not much clothing, but GOBS of baby Raider gear. I went to the one in Frisco and found lots to fill a gift bag for a friend.