Hi,
I have done pin parvati trek in September last year. It can be done without Porter or guide, if you know the route after mantalai lake. Till mantalai lake its pretty straight forward. From mantalai lake to parvati base camp, you are much likely to get distracted. Thus if you are first timer on this trek better to get a guide from kasol who will take 1500 per day. Need of Porter is completely up to you, we carried weight of 15-20 kg. If you are not comfortable with carrying this much weight for a distance of 110 km (total distance from parvati Valley to mudh) then you must hire porters as well. Remember after crossing khir ganga you are on your own, depending on the time of your trek you might not meet another human at least till you cross the pass, we haven't.
Best of luck have fun you will enjoy it that is for sure