PAROS -- I would recommend that you stay in ANTIPAROS ... it "ticks all the boxes" for you ... I've visited Paros about 5 times (mainly because I had newcomers along who wanted to)... I have stayed walking distance from ferry, in Parikia the port town, or walking just N along the water to Parikia beach area, just for convenience & no need for car. Must say, Parikia beach is NOT that great, in late may not well-groomed, and seaweedy. Later in year, there are "caiques" (small boats) that go to a nicer beach but not at your dates.
By contrast, Antiparos is charming right from the moment you step off the ferry at its tiny pier ... I stayed just across a little bay from there, at a hotel now called "Sunday Hotel" -- it has lovely front rooms with canvas-awning balconies, to sit & gaze & read. Has A/C (BTW most rooms do these days), but we didn't need it, because of lovely breeze 1st week of june. Also next door, Mike's Place equally attractive. Both are family-owned maybe 12-18 rooms max. Walking distance to the winding lane (called Agora = market street) that wends inland and all the way to the sunset side of the island ... by evening it is downright enchanting. There's a small beach by Sunday/Mikes, but on other side of very, an easy walk to a lovely sandy beach very low-key in late may (when I was there, sunbeds were in a stack & we just went over & got some). There are lots of nice tavernas on Antiparos --. My fave was Pentelis .... I took fellow Naxophile "stanbr" & his bride there, & he liked it so much he ordered FAR more than we could eat. Also check out recommends from Antiparos expert Heimdall: Argo, Yorgis, Pavlos Place for grilled stuff, Kyklades for slow-baked oven dishes.
Staying in Antiparos, you can have y our cake & eat it too. Quick transfer @ ferry pier, 20 min ride to Antiparos. there's also an even quicker, more frequent ferry (10 mins) called Pounta... it's met by a bus that zips you to the front street of Parikia. Tht way you can day-trip to check out Parikia highlights ... huuuge Cathedral, various ruins, cute little museum (tho collection not as fab as Naxos' tiny GEM). U can also take a bus up to see Naoussa... once a fishing village, but now very postcard-pretty for tourists. If you crave nightlife, Parikia at your time is best bet... bars & some clubs w. music ... the ferries run late enough to party & still get back to serenity of Antiparos.
NAXOS -- You say you have been there before?? Did you stay at Studio Castellos before??? I'm wondering... I remember I was attracted by its online photos, it was on Ag. Anna beach, correct me If i I was staying on Ag. Giorgos (which I like best, in Late may/early June) and I take bus out to a far beach for my swims. I remember going to Ag. Anna, so decided to look over Studios Castello, and it looked (from patio toys & swimsluits) to be a favorite of families w. pre-schoolers... maybe that's for you, these days I llike to be near toddlers on beach, not in next unit. Also, my 2 visits to Ag. Anna, both in late may/early june, have left me unenthused... the beach is narrower, and also was very crowded, even at that off-season period. Sands seemed to be lined with tavernas that played overly-loud music. I could barely find space to lay a towel. And when I walked down the beach for more room, some seaweed, & rocks at entry. Nothing too bad, but just not up to PLAKA or Ag Prokopios, IMHO. Prokopios has wide sands LOTs of sunbeds, great for swims (at waterline, it drops off DEEP 6 feet out) ... Main drawback to Ag Pro is that many hotels are BACK from beach several hundred yards & you must walk down busy road to get to sands (and going back is uphill a bit). Best-located hotel there I found was Liana Hotel. check it out. RIght across a dirt road from the sands, and has nice landscaping.
