This chain lock I got at harbor freight for $15. Target sells the exact same thing under BELL for $30.
For disc locks, I like the vending machine style keys.
I also have a BELL rubberized steel braided w/ Kevlar cable lock. It's about half inch thick. I wouldnt go with anything smaller in diameter cause bolt cutters will go through small stuff like butter and barely make a "clamp" noise. I believe its actually quieter cutting braided steel when there's a rubber coating so you'll never know its been cut.
My last lock is a special one. LOL It's almost the same as this but with a big black plastic covered end with key hole cover. 1/4" fits right through the holes in your rotor. I use this on my rear wheel since even if you have a disc lock on the front, all they have to do is pick up the front end and roll her off. Just make sure to flag it or get a stretchy line like the disc locks have to you dont forget it.
http://www.harborfreight.com/cpi/cta...emnumber=97149
For the first lock pic. You can always go to a hardware store and get the size chain you want and cut a sleeve off a long shirt/sweater to cover the chain, then use the lock of your choice.