Gap, Old Navy, and Banana Republic all make ankle, regular, and tall trousers. There ends my sphere of reference. If you are shopping second-hand and see a Gap or Old Navy pair with an A after the number on the tag, that means you found an ankle-length pair of jeans or khakis. I'm not sure what the designator for tall is, though.

especially since I think I just want the one chuck of hair that always falls in my eyes. :)

Clip or pin the hair around it back. When you have the bleach on that section, clip a plastic sandwich baggie or little pouch of sandwich wrap loosely around it and pin it to keep the bleach in and the world out. (I recommend the sandwich baggie, myself. That's how we do Aliyah's streak.) Do the same thing when you have the purple on your hair. It protects your face.