Why should a food be trafe because of an external factor? If you want to
say that the Mitzva came about through a forbidden act, then you may have a
case (of a Mitzvah coming about through an Aveira), but here there is no
forbidden act involved in the Kashrus process. There is a Gemarah in the
first chapter of Sanhedrin that discusses if someone stole grain and then
made bread out of it. The Gemarah asks can he make a Bracha on [separating
Chala from] it? The answer is that a bracha like that would be
deplorable...because the grain it's made of was stolen in the first place.
I don't think the cases are comparable at all. There was no forbidden act
involved in the bread itself at all, nor in the money. If you don't want to
use money with his face on it, fine... but I don't think it is a Halachic
issue at all.
<<Is food purchased with a $20 bill kosher?>>
I don't think there is any reason to say no.
Etan