For future proofing (2yrs etc), u need to be looking at a 1366, 1156 is already 1/2 dead. You will likly find the new i9 will be 1366 so that would give u a nice upgrade path.
can you prove the 1156 is 1/2 dead? Even though there nothing being shown from intel 1156 cpus, doesn't mean that there no plans for it. Im pretty sure there will be future cpus on this socket that may even get 6 core (and maybe more).