I would suggest that you look into staying at Wyndham Bonnet Creek in a 2BR villa. You'll have plenty of room to stretch out, plus a full kitchen and laundry. My DD21 loved it when we stayed there 2 years ago. Both boys will have their own bed in the 2nd bedroom and you'll enjoy the king bed in the master. Uber/Lyft is a good alternative to Disney buses. Plus, Disney is getting rid of free Magical Express at the start of the year so you'll have to pay for a ride from the airport in any case. They *do* have transportation to the parks, but I think Uber/Lyft is cheaper. Here is a thread about the resort:
https://www.disboards.com/threads/the-we-loooooove-bonnet-creek-thread-part-4.3366139/
If they'll share a bed, then a DVC studio will probably be OK. My DD21 did fit on the little murphy bed at BWV that sleeps a 5th person, but she's short. I assume that your boys won't fit. If you go for a DVC studio, I would probably try for one near Epcot or SSR (near DS). We stayed at BWV last trip with my DD and she enjoyed going into Epcot to try to "drink around the world" (over multiple days on our insistence).
If they won't share a bed and Disney bus service is that important to you, then stick with Pop Century which is on the Skyliner for 2 of the parks.