Sold in separate versions for the iPad 2/3rd-Gen and current fourth-generation iPad, Belkin's new ThunderStorm ($200) offers an interesting solution to a common enough problem: finding a way to protect an iPad, stand it upright as necessary, and watch videos on it with respectable audio quality. "Respectable" is the key issue, though: if you feel that your iPad already has sufficient volume and sound quality for your needs, or are looking for…