generally, you don't need to (and shouldn't) use a setback seatpost to fix reach, as it will effectively change the seat tube angle. of course, a more lax seat tube angle isn't necessarily a bad thing. it might even make it more comfortable, but it will change the way you pedal. if you feel cramped, just get a longer stem. it looks like you're riding, what, a 100mm? try 120 maybe.

apologies for lack of clarity. i've been drinking.