I'll be the first to jump in here with my 2 cents worth. If you are wanting to contract a knife made then I would recommend that you leave the type of steel up to the maker. Both of the steels that you have mentioned are top quality steels but so are many others. Naturally you want the best performing knife when you decide to order but truthfully the quality of the finished knife is more contingent on the makers ability to get the most out of a particular steel than it is the type of steel used.
Do some research into makers and their abilities. When you decide who, then tell them what you expect the knife to do and how you will be using it. If they are experienced then they will know how to give you what you are after. Don't handicap the maker by dictating a type of steel to use. Let them pick the steel. Dictate what you want the knife to do. In most cases you will get a much better knife this way.
To answer your question, there is no perfect steel. Only steels with known qualities. Both of the steels that you asked about can be made into a top quality blade. Getting a steel blade to have exceptional edge holding and toughness can be done with many various steels if you know how. The type of steel will dictate how you make the blade much more than how good it will be in the end. In other words a steel is no better (or worse) than the guy using it and what he/she can make it do.
Also, you mentioned clay hardening. I'm assuming that you are interested in a blade with a differential H/T. Clay coating a blade is a technique that can be used for this but not necessarily the best in all cases. When done correctly it can give you the ability to bend the blade 90 degrees without breaking but isn't the only way and not necessarily the best way, only one way. Once again let the maker know what you want the knife to do and let them determine how to get there.
Gary
