H70/H80/H100 isn't something most of us consider 'watercooling'...they are usually classified as a self-contained liquid cooler. I know that sounds like they should be the same and they do use the same concepts, but performance and build is nothing the same.
If you are 'afraid of leaks' then you shouldn't be considering any kind of liquid/water cooling at all. That being said, I'd put 100% of my trust in a loop I designed and put together myself over any Corsair or Antec boxed cooler.
When it comes down to it, neither air or any liquid cooler will cool any lower than your ambient room temperature, simple as that. Most good/great air coolers perform about as well as the H100 with fans set to medium or high, and are much louder at those levels. So, in essence, you can spend $100+ on an H100 or $60 on a great air cooler (or less) and achieve about the same cooling performance.
Well noise is not an issue but I'm going for a quiet system, so to be able to game without headphones, and the desktop is going to be near me so, being a bit quieter is very good.
I'm not afraid of water leaking, but I've built a lot of freshwater aquariums with custom pump systems, and never had any problems, but on some closed loop coolers threads I've read, there are people claiming very high leaking probabilities, around 20%, so I was a bit concerned by that.
I'l go for one of the H100/80/70, and make sure to seal all surfaces a bit better with aquarium equipment, is the Haf 922 big enough/good for any of these coolers, more precisely the H100?