I never saw your question to me sorry... Since this is going to be temporary, the led's seem the way to go definitely, especially since you can actually use them for something else afterwards. I don't know if those leds are safe or not, and looking through amazon, looks like most manufacturers omit the minor details of importance to us at the moment. Since you will be doing this for fun and i think you should not loose sight of that as your main objective, the led bike light on amazon, is sufficient enough. It looks like a red casing over a white led, so i'm not sure. but what you can do, is point it away from your working area so that you get just enough light to see what you are doing. if it is still to bright, then put a white piece of paper or something translucent, so that you still get light but not as strong. Remember, your not making technically perfect pictures, and i doubt you'll get much fogging, IF ANY from this led light, as long as it doesn't directly hit your working area... Just something quick.... when i worked alone in the darkroom at school. i would put the paper in developer 1st step... and wash it... once washed for a couple of minutes, the developer is gone. so for my first practice prints, i would turn on the light or take the sheet outside to see my exposure. OF course, don't do that, but what i want to say, is don't worry much about fogging the paper. it's only for a couple of minutes, and most likely won't happen, and even if it does, it won't be noticeable.
As for the plastic containers... those are fine, in photography, we want strong durable ones, because we'll be using them for a while, and so they become brittle over the years and eventually crack, but we'll have gotten our money's worth. You, on the other hand, only need a container for one time use... i suggest the cheapest one that can get the job done... these seem good for that... the cheaper the better.