Of all those choices, Klonopin (clonazepam) would be the best choice for panic attacks. The reason is that compared to the other benzodiazepines that you mentioned, Klonopin is long-acting and has less of a euphoric effect, so you only need to take Klonopin twice or three times daily to deal with anxiety attacks.
Compare this with Valium (diazepam), which is also long-acting, but it produces more of a euphoric effect ('high' feeling), given Valium is more lipophilic than Klonopin, and therefore Valium more rapidly penetrates membranes (blood-brain barrier), and hence the rapid absorption into the brain. So the high lipophilic properties of Valium makes it so highly addictive.
If you also compare Klonopin with Xanax (alprazolam), both are highly potent, but Xanax is very short acting, thereby making it more addictive.
Ideally, you should only be on benzodiazepines for a few weeks, then discontinue it, to let other effective, long-term treatments take its place, such as CBT (cognitive behavioral therapy) and SSRI medication treatment.