It seems to me that people designing kitchens have a lot of the technical side of the project to think about. Pretty much anything you find on the Mac will give you tons of creative control, minus the specificity of the kitchen. (does that make any sense?)
Have you tried googling it? You also might want to search here:
http://guide.apple.com/index.lasso
As a 3D animator I know of a lot of 3D modeling/animation programs, but none will have the cost planning etc features that 20-20 has.
Looking at the features of the programs mentioned here the Alibre program looks actually very impressive... budster's second link looks iffy I think though.
It seems to me that what you're really looking for is somehting that can do CAD as well as give you cost planning/management etc features.