This is too funny. I have the exact same dilemma. I decided to go with Sproles and Murray. Bradshaw has been very consistent and the Giants commitment to the run lets you know he will get his touches, however, all indications are that Jacobs will be back for this game so that will take some of the touches away from Bradshaw. In addition, through Miami is a god awful team, their run defense is not that bad. About average actually, unlike the Philly run defense which is horrendous.
It would be nice if someone who actually saw the Dallas - St. Louis game would comment on Murray's performance. Was it all the blocking or did he have to make some moves and break some tackles to get his yards? It may be easy to say, the Rams defense is just that bad but for a below average back to run for 250 yards is really unheard of. If you look at all the backs who have rushed for over 240 yards you'll see that they are just about all pro-bowl caliber backs. That puts Murray in good company. Not saying he is a pro-bowl back, just saying it may not have been as much of a fluke as it may have seemed.
I hope I'm not leaving more points on the bench than will start but considering my match up this week, I need as much of an edge as I can get.