I went through a similar exercise with an E140 that I wanted to use for bass guitar in larger rooms than my 12" Portaflex cabinet could handle. I read up on the speaker specs, used a
box calculator site to try to determine useable dimensions, volumes and port sizes. I thought about building an EV 606 cabinet (good plans are available).
You are likely finding out that there are some important variables here, and the decision is not as straightforward as I would have hoped. As PRR was saying, it is a compromise and in the end, you need to be able to lift the cab and load it and still be able to stand up and play for three hours. I could not pull the trigger on any idea, but I kept searching online for a decent cab. I found a large Peavey for cheap with blown Black Widow speaker. I tried the JBL in it, sounded very, very good with my amp so I am satisfied with it. I need a hand truck to move it, but am used to that.
To your question about the Rumble cab, the quick answer is "try it and see". For a more detailed answer about the port size, you would need to know the inside dimensions of the cabinet, the port size, the volume that the speaker itself displaces, and the resonant frequency that is optimal to tune the speaker to. All that stuff can be figured out using online info like the link I used and the ones kagliostro offered, or.... you can try it and see.