You would definitely be better off buying two shorter chains rather than one long chain. With one long chain that goes through both wheels and the frame you'll be wasting a lot of chain just covering the distance between the wheels. Plus two chains gives you more locking options.
And while a 16mm Pragmasis Protector chain is an incredibly secure choice (if paired with an equally good padlock), it's completely impractical for mobile security. For example, the 1m long Protector chain with a Squire SS65CS Stronghold Lock weighs 12.13 lb (5.5 kg). That's the equivalent of nearly 15 cans of Coke!
I think a 10mm chain is about the limit of what is practically portable as an every day chain. The Kryptonite New York Noose is a good choice because the noose design means less chain goes further. You might be able to get away with the 30" (75 cm) version.
But you would still need another lock. Maybe a U-lock would be better for a secondary lock? Or have you thought about two U-locks? Whatever you choose, I wouldn't recommend anything rated less than Sold Secure Silver.
I run a website where you can compare the lengths, weights and security ratings of some of the most popular chain locks. And U-locks too. So let me know if you need anymore information!