Using Street Art in a game

OK .... would anyone be able to suggest any street artists that might be willing to allow some of their art to be used in a free Mod for the Fallout Game?

Some guys are creating Fallout London, so I wondered if anyone could think of bits of art that would be suitable, ie London based artists whose art might work in a fallout post apoc setting.

And if the artists would be approachable to allow the use for the free mod?

Suggestions on who to approach and bits of art would be greatfully recieved.

Perhaps immortalise some buffed art ?