I've owned 07, 08, 09, modded all of them.
I'd go for 09. You can get them without the sally 162, the changes to 2010-2011 were VERY minimal, and the 2009, of the ones I've run with, was the strongest runner.
IF you can find a 2007 that has the original ECU (you'll never be 100% positive) and doesn't have some other issue, you'll be doing well, BUT... then you've got to spend a few grand just trying to catch up to the updates that the 2009's have for free, and you can't do engine reverse while keeping the original ecu mapping... so you lose there no matter what you do.
09.