Your scoring goal is very reasonable within the allotted time. If applying fall '17 (to matriculate '18) I recommend taking the June sit (more prep time, disclosed, still allows Oct retake) over Feb (undisclosed). Best:)
I'm aiming for a 175+ but would be happy with a 174 :) Though I should add that I work full time and I'm aiming for June '17. Sending out apps in fall '17.