Question about Golf Irons, GPK?

[IrishofNDMan]

I have Callaway Big Bertha Irons (2002's) and my brother tried them out and hit well with them. He is going out soon and getting new Irons, and he has already tried a few out at the range. He is looking to spend about $400 or less on the Irons, any suggestions on what is good out there right now? He is thinking about some Nike Slingshots but I told him I wouldn't get all wrapped up in the Nike name, but it's ultimately up to him.