Gina.
If you are needing the best white, use the kona, I fell in love with it a long time ago. I use it for quilting and for applique, you can't find better. Its a little more expensive, and if it to much, then go with the muslin. They have some bleach muslin, that is very good quality. I just bought some, just hold to light to see how flimsy it is before you buy. Its not that much a yard. And if all else fails, go to the while on white. You can either use the design or turn it over. You can get Muslin and Kona cotton at either Joanns or Hancock fabrics. Joanns you can use your coupons. Hope this is helpful to you.
Rita