I would say a mixture of all of them. Basically the difference between the proteins is the quality, the speed of digestion, and the rate of release of the protein itself.
Whey protein is generally best used for post workout since it is quickly absorbed and amino acids are quickly available to the muscles. Caseinate proteins are proteins that are realeased much slower, over the process of ~4-7 hours depending on the study. This is why foods such as cottage cheese are eaten before bed, to keep you anabolic with a steady release of proteins while you sleep (remember sleep=growth). AlltheWhey, a board sponsor, has a lot of different protein mixes.
There is no clear cut protein for cutting, it just depends on whatyou are using it for.
If you are using them more as a meal replacement, then definitely get a mix of various proteins. If you are just using it post workout you can stick with Whey.
