Making seitan yourself is much easier and cheaper than buying it. You also have control over the seitan's seasoning. It may seem time consuming, but it actually requires very little attention. If you can't find vital wheat gluten flour, there are many websites that sell it. I bought my flour from www.bobsredmill.com.
This is a great high-protein substitute for chicken or tofu in any meal. My favorite way to prepare it is to roast it and serve it with veggies and some kind of grain. It's also great and easy to prepare in stir-frys.