Hi if you are looking to go into target cutting compititions www.bugei.com
has a forum on their web site dealing with this topic. They can give a lot of advice about what type of swords are best for cutting, they are a little bias about their own line of paul chen swords but they should be. Most of there line of swords were designed for heavy cutting and compititions.
My advice is stay away from practical katanas and Kris. They were not designed for compititions. The Sword Armory swords, I havn't heard alot about them so I can't say one way or the other. They state that someone using thier "tsunami" won a tameshigiri compitition. Now I don't know who sponsered the event and who all competed but I am sure the guys at bugei will tell you all about the event if you ask them.
I hope that you are taking a traditional Japanese sword art. You just cant enter with no experience. If you are taking one you should talk to your instructor about what you are doing and get advice from him or her.