Hi Peter,

Unless you want to go with the expensive types recommended up top of the post, the foam wedgies you point to in your link are seen in a lot of rehearsal studios around here and seem to be quite popular.

At the Sam Ash music stores here, that is what they use to cover the walls in the rehearsal studios that are next door to one another. Folks seem to buy them out like crazy for their own home studios too. They are also pretty cheap. (The "Auralex" versions are the ones you will get around here.)

It may be all your need unless you need a $100,000 home recording studio.