Okay, so he's American. Seems likely to start in London or someplace near it, if we wanted a more quaint sort of feeling. *nods*

To be honest, the whole Master arc with Ten never appealed to me. It sort of escalated quickly and then fell apart soon after, so I never really got the "charm" of him as a foe. Or potential ally. For autons, you were thinking Living Plastic yeah? It wouldn't be that hard to bring them into play I think, considering plastic is all around us these days. 

Daleks and Cybermen are likely to come into play, though hopefully not too soon or it might turn off Max, since well, anyone ought to be scared of those killers. 

As far as episodes which may be easy to start with, "End of the World" (with possible tweaking to allow the Doctor and Max not to be too separated) or "Beast Below" may work? Or even "Unquiet Dead"?