Well, using watercooling and not using watercooling is all up to you. Is it too dangerous? That's up to you to decide. Also, whether you use a 300 dollar watercooling setup or a 100 dollar watercooling setup, your chances of breaking something or leaking water or anything are still the same. Keep that in mind.
Back to watercooling. First, I don't recommend ordering from TigerDirect. Also, 5 1/2" bay watercoolers are usually pretty bad. If you really want to go watercooling, expect to spent around 200 bucks to cool the CPU alone, otherwise you might as well go with high end air. The only "all-in-one" kit I would recommend is the Koolance Exos series. Otherwise you should build your own kit using Dangerden's custom kit builder or just ordering the parts yourself.
Watercooling is fun, especially setting it up, and it definately cools well. But you have to remember, where there are pros, there are also cons. Out of my own experience, here are the pros and cons I've seen:
Pros:
Cools well - Of course, it's water!
Looks sweet - Can't deny that this is a pro!
Fun to set up - Some people don't like setting up watercooling because it takes a work and concentration, but the best part to building a computer, at least to me, is the building part!
Dust buildup goes way down - Since you don't have as many fans in your case as you used to, you get much less dust.
Cons:
Expensive - Definately more expensive than air.
Loud - A large misconception of watercooling is that it's quiet, but unfortunately it's not...the pump itself is usually around 35 - 40dBA, combine this with the high-powered fan for the radiator...
Maintenance - Sure, it's nice not to have to dust your comp as often, but remember to replace the water once every six months and do a full cleaning every year.
It's still water! - You absolutely have to be careful when you have water in your comp at all, no exceptions!
Watercooling is fun, but it's work. It's like building another whole computer in itself. Give it some thought, and once you've decided that you really want to use water, you can ask anyone here in the forums if you have any questions - most of us are pretty knowledgeable.
