I never knew the feeling of losing the school darkroom to the summer because i set up a darkroom in my basement during my first semester of photo class. If your going to do this, i would say use the bathroom, it is very nice to have running water in the darkroom. I'm afraid that if you don't have running water you will get frustrated. As for choice in chemicals, I'd say go liquid, and get a graduated cylinder as well. That way you just mix what you need each time, and then if you don't use up the whole thing before the end of summer, it won't go bad as quickly. I would go for adorama brand chemicals. They are pretty inexpensive, and work fine. I have been using the same bottle of adorama indicator stop concentrate for over a year now, with no problems. The working solution lasts a fairly long time as well, up to probably 3 months, depending on how often i print. Also, i would recommend buying the plastic tongs. Just get two sets of two, that way you have 4 tongs, leaving you an extra for the wash. The bamboo tongs tend to break, mold, and fall apart. And with trays, I would get something like the patterson's with a ribbed bottom, so you can more easily pick up the paper. AND, with safelight, get one of the 5x7 premier ones, they are very nice, and not super expensive. I have 4 of them in my darkroom.
Hope this helps,