You want to make a jump from a highest 152 in practice to a 165 on the real thing. That's aiming high (though not to say that it can't be done).
I would really suggest option A. You are not going to be studying for the LSAT 24/7, if only because there's really not enough questions from the past tests to keep up that level of study for more than a month. Go for the part-time job, and aim to have about 30-40 hours or so per week to study for the LSAT (sorry, there goes your weekend). Keeping your job will help you financially, of course, but it will also be something to take your mind off of the LSAT - otherwise, that's going to be the only thing on your mind for those few months, which is not going to help.
Are you planning to take an LSAT course, or just self-study?