Hi,
I believe there already is the functionality you are looking for.
Do you want to quickly have options to pick a material for objects which have some material applied?
In this case, you can use CoronaSelectMtl - you plug multiple materials in it, and apply it to objects. Later, in CoronaSelectMtl, you can pick which material you want to be applied. It is very handy.
If you want to change a material already used in the scene, without "saving" it, you can use "Change material/map type" in 3ds Max material editor - it will change the selected material with a new default material/map you will pick. All the objects which had the original material will be affected.
Hope this helps.