Is this a good fantasy football trade?

I need a runningback. My receivers are deep, I have Calvin Johnson, Steve Smith, Anthony Gonzalez, and Donald Driver plus Bryant Johnson if I need to stick him in somewhere. My Runningbacks are Larry Johnson, Earnest Graham, and Maurice Jones-Drew plus DeAngelo Williams who I think lost the majority of his carries last week. I've been offered Steven Jackson and Jamal Lewis for Calvin Johnson and Maurice Jones-Drew. I'm not sure about this one, and I'm thinking about countering and offering Calvin and Maurice for Steven Jackson and his other RB Matt Forte. What should I do and why?