Graco RoomFor2 (or any sit and stand, really) - we had a City Select and my older one very quickly outgrew it, was also way too heavy and heard to fold. The Graco was cheap, 1-hand fold, and lighter.

I used double bob with my 2nd and 3rd (4 year gap). I used it a lot of jogging or long walks. I was very happy with it, though only used it until older one was a little over 5. I had mine from when my first two, who were 21 months apart, but don’t think I’d have spent the $ on it for a larger age gap. If I were you I’d buy secondhand.