Usually if you can find Chinese grocery area, there might be a chance. Check and ask Chinese stores around Garland city area from your yellow page. You might find the possibility to buy Yixing teapot and cups.
Green tea is part of my daily life. I purchased area famous tea in China and keep it in freezer. I enjoy pure tea leaves, no surgar or cream, no herb or orange. Sometimes I also enjoy jasmine green tea.

i find a website by yixing local offering various kinds of yixing teapots,you could visite and have a look
http://www.yixingclayteapot.com/