I'm not sure how tall your kiddos are but my son is 4, 49lbs and wears boys small and medium shirts. He is on the 3rd to the top slot of his FR85 and 2nd to top slot of his HD360.
I actually tried him out in a bunch of doubles this weekend. I found that for all of them, he is obviously at or above the weight limit. Pushing him in the store wasn't a problem for any of them... but smooth floors always help
His height and leg room for each was the bigger issue.
Graco Ready2Grow Stand and Ride Double Stroller: This was by far the funniest one to try him in because he couldn't even fit in the front seat. Even if I were to remove the front tray off for him, the seat is incredible tiny front to back and the leg room made his knees come up past his chest. This was in no way a go for the front seat. He fit on the back seat of course but for your situation, the front seat alone rules this one out for you.
Baby Jogger City Mini Double: when the seat is reclined all the way back, his head hits the back window and his head is even with the back. When he sits all the way up, he has a good 2-3" (I'm a bad guesser and I didn't have a tape measurer). He had okay leg room if he had his legs bent or sat kinda cross legged. But he couldn't stretch out his legs without them dangling off the end.
Britax B Agile Double - Pretty much identical to the BJCM.
BOB Sport Utility Duallie - Same height as the BJCM but more leg room. The canopy if folded all the way back caused my son's head to be above the back.
BOB Revolution SE Duallie - Same height as the other BOB but much better leg room.
Bumbleride Indie - His head falls off the back if the snaps aren't done on the flap. His head had a bit of room before he hit the canopy sitting all the way up. He had the least amount of leg room, but just by a smidge, compared to the BJCM. He actually told me he liked that one the best, he said it was the most comfy, so of course, it didn't work.
Out of the ones I tried him in, I liked the BOB revolution the best, but still wasn't in love.
Good luck and let me know if you find something! We're expecting our second baby and DS will be almost 5 but due to poor motor control planning, he still needs a stroller for walks longer than 5-10 minutes.