Hmm don't take this the wrong way at all, but I think you should look at spending a bit more money if you're looking to be a serious detailer. I just turned 18 and started detailing when I was a junior in HS, too... then I probably had over $1000 worth of products and tools. As you will see here, the general idea is that results are achieved through process, not the products you use. However, looking at your list, you seem to be lacking many of the necessary products to use on an average customer car. I would definatley find a way to gather a bit more start-up capital... or at least put the proceeds from your first few details right back into the business. I'm not saying thousands are required... however, for $250, you can barely get a PC, pads, and another product or two.
Very organized ideas, though! I'm really trying to grow my business this spring... if your bored and want to chat about some of the difficulties of starting a detailing business in high school, drop me a PM, lol... we're probably goin through the same problems