Kinda late to this, sorry. I have an Alpicool C40 that I grabbed for 280 on Amazon. A lot of them are essentially all the same, just rebranded. If you've looked at a few different brands you'll see it. I love mine. I've had it for close to a year running 24/7 since then. Only one zone, but you can set it as a fridge or a freezer, control it by bluetooth, has TONS of room, and barely draws any power.
Are you planning on running a fridge off of just the cigarette lighter, using the vans main battery, or do you plan/ have an auxiliary battery? I wouldn't recommend any compressor fridge if powered by the starter battery. It only draws like 45 watts from what I remember, but a regular SLA starter battery isn't going to power it for very long before killing it.
Just came back to the forums. Half assed built my van out, mostly focusing on electronics and solar. My system might not be perfect, but I can help walk you through different setups and what they can handle if you're still looking.