From what you’ve said you’re going to need a couple of kettlebells to cover all exercises.

I would recommend getting a couple to get started, either:
a) If you want to do lower reps and focus less on cardio, I would recommend a 25lb and a 35lb.
or
b) If you are interested in doing circuits for mixing strength with conditioning, I think an 18lb and a 25lb would be fine.

Kettlebells are different to normal weights because the challenge your main muscles and all the supporting muscles, tendons and ligaments. So you don’t need a super heavy kettlebell to get the proper effect.