Two soundcards?

For various complex reasons I want to run two soundcards. However,
although it can be done, I find that having to go into the settings to
switch between them is a bit cumbersome. Especially having to explain
it to the kids!

So, is there a way I could assign a shortcut to a key on my keyboard
that switches between the 2 sound cards (or a simple click of the
mouse somewhere)

OR

Is there a way to configure things such that my PC defaults to one
sound card when using Itunes, and the other for everything else?

Thanks in advance.