I may be mistaken but I believe 07 was the first year of the 96" and may have compensator issues, so I would keep away from an 07 even tho you may be able to find a jewel for the right $. I just have never liked getting the 1st year of anything just because it's new and may have issues. JMO
The 96" motor was introduce in the Dyna line in the '06 MY and available in the other model lines in '07. The '07 year was the year that the MoCo outsourced crank manufacture/supply off shore and the MY had a higher incidence of crank failure than previous years and, for that reason, I would avoid used '07s. I am not up on changes/improvements in the Dyna line from '08 to '11 but like jamesearl says, miles and condition should drive the purchase.