It would depend on what they carry and if the tan is homozygous, but you will certainly get rumpwhites, black tans and possibly blacks (if there is only one dose of the tan gene). You might get other colours too if they carry other genes. Same goes for satin - it depends if the rw carries it, otherwise they will all be normals carrying the satin gene.
I've bred tans in most colours with cavies but the mice are totally awesome, couldn't believe my eyes when I saw my first b/tan rumpwhite it's really not supposed to exist but it's wonderful, I love it
I agree with you about the black/tan vs choc/tan, the bigger the colour variation the better