Custom user icons for address book

[Arie]

I would like to find a set of custom icons which I can use as user icons in the address book on my iPhone, so that when my wife calls for example I see a heart, when a colleague calls for example I see an office building, et cetera. Something like that. I cannot seem to be able to find pre-made sets of such user icons however, nor am I able to find others who want this as well. Of course I could gather a bunch of images which I like and use those, but I would like to have a nice large set of icons, which match each other in style. I could not find anything myself, so I am hoping anyone here can point me in the right direction.