16kg. Most versatile, most usable for as many reps as I want to do for 1H swings, presses, get-ups, snatches, squats, cleans, bent presses, windmills, 1-leg deadlifts, and easy 2H swings. And it doesn't intimidate me when I'm feeling less than strong, or not warmed up.
Well, assuming we could do bodyweight exercises, run and/or sprint, I would choose the 32 kg. A bit heavy now but I would grow into it. I would use the 32 for strength and run/sprint for "cardio." Eventually the 32 would start to feel light and would be more strength-endurance, but the 32 would be pretty tough to outgrow.
Funny, I now have only one pair of KBs and they are 32s. I don't really feel the need to get another pair (but we'll see). My logic: however many C&J reps I can get using a pair of 32s I should (at least) get using any smaller KB pair. Plus I can always supplement with a lighter or heavier barbell.