Double stroller or stroller wagon?

I have been reading about so many strollers but I need help. I currently have a tall 11 month old.

We watch my best friend’s baby a few times a week while her mommy is in college. She is 9 months.

I want a double stroller to take both of the babies out for some fresh air! I also plan to have another baby eventually so I feel like a wagon or double stroller could be a good investment.

I have been considering the wonderful or kenz for some time because it seems great for walks, outings, and grocery shopping. The weight is not an issue for me personally. I like that you can add and remove a seat depending on what you need. The drawback is a wagon is not as compact.

The problem is I am trying to find something second hand. I have almost been scammed twice trying to get a wonderfold. I keep coming across the city select double stroller on fb marketplace. The configurations look great— especially the fact that it can convert to a single stroller when I only have one baby with me.

The current stroller I have is a graco, and ever since my 25lb baby has gotten bigger… the stroller is a little creaky and squeaky. Also, the seat does not seem that comfortable for my son.

All that to say, what strollers or wagons are parents of two little ones using??

I’m looking for durability+ somewhat affordable secondhand+ good steering+ comfortable for the kids. I don’t really care about brands! I’m also open to jogging strollers as long as they fit through a standard doorway.