if views of fireworks are a "must have" then Poly has your best combination of 1 and 2. VGF has some standard studios that are lovely and large, and may have a view of the fireworks, but view from the room is not guaranteed. But you can easily walk to the marina and watch fireworks from there. BLT has theme park and some lake view studios with views of MK fireworks, and the roof lounge to watch fireworks from, BUT the studios only sleep 4 and are tiny.
BWV has some studios that can see fireworks at DHS or Epcot, but not both parks at the same time, and those views are not guaranteed.
So for all that, I think I'd say Poly for you, so long as you would be ok not having a home resort advantage for a 1BR. Alternatively, I'd look into points for a resale contract at BLT with enough points for a lake or theme park view 1BR. The 1BRs at BLT have 2 full baths and sleep 5, and you can get a guaranteed view of fireworks from your room (and also easy access to top of the world lounge on the roof)
Also - you might want to edit your post to add a poll (if you can) - then you can see what people vote. Good luck!