You will need to book Theme park view if you want a fireworks view. Patio is ground floor, which means no elevator but less privacy from passers by. We prefer the third floor balcony for privacy and nicer views.
If you plan to stay in the Poly, are you interested in staying Club Level? That would put you in Hawaii, which is an excellent location. Also, I believe that you all would get an extra 3 FP+ to use each day. Finally, with 5 in one room, you would get free breakfast every day (continental) which would really help offset the extra charge for CL. Add in free beverages, snacks, evening appetizers and desserts and you are doing pretty well. Book a pool view room for the lowest price in a CL room. Plus you will have the lounge to spread out in if you feel cramped or to meet up in or to wait for others when getting ready. The Poly has the best lounge with beautiful views of the MK and fireworks.
You are welcome!