The D1sc is a better blower because it can push more boost without spinning as fast. However, the P1sc is all you need for a stock bottom end.
You should upgrade to the 3-core intercooler no matter what boost you plan on running. Not sure how many cooler options they have, but I was under the assumption it was 2 and 3 core. In any case, the bigger the intercooler the better to keep the charge cool.