I have these. I was looking for something smaller to fit the kind of stuff you listed, but these were inexpensive and had good reviews. I've used them for over a year and am glad that I bought them. I find that the size is convenient for carrying things that I didn't anticipate (like a week's worth of dirty laundry on Friday's). A few downsides: 1. They are saddle bags, not individual panniers so you have to ride with both sides. 2. They are somewhat easy to remove and reinstall, but this takes some patient practice. 3) Not waterproof (but who cares with dirty laundry.

It's interesting that you are looking for "lightweight" panniers as they are all pretty much lighter than the rack they mount on and the stuff you put in them.