Well, let me attempt to give you a rundown on water vs. air.
The ol' staple. Active air cooling has been around since computers existed. Now days theres enough options to make most computer users very content, from ultraviolet activated colors to LEDs to 113 CFM.
The downfall of a fan based cooling system is sound. Many computer fans create well over 35db of noise in order to move the proper amount of air, multiply that by four or five whirring away and its enough to drive some geeks nuts.
However, a well set up case with proper air flow CAN be quiet and efficient. It is the mix of case design and fan layout. A fantastic example of this is Lian Li cases. Well laid out with fans in all the right places (the 6077 which I just ordered is capable of holding 5 fans AND has a ground intake). Mix the right fans in, and youve got yourself a nice cool system.
What I have not yet adressed however, is the heatsink/fan combination. There are so many to choose from, and everyones going to tell you something different:
"you must have a copper base..."
"It's all about airflow over the heatsink"
"stock fans will serve"
Youll catch something from everyone. As far as this goes, its a matter of what you care about. Again, is sound going to bother you? Is size a matter? Does it have to look purty?
There are options that are quiet, cheap and efficient (vantec makes one for AMD for $25 thats awesome) if you want to just play it safe.
In the end its a matter of taste at every turn, but one thing must be stressed: no matter how much air the fans move, no matter how loud they are- if they are not properly placed in a case it wont matter anyway.
Sonds quite scary doesnt it? Truth be told, its quite safe nowdays. With great kits from companies like Swiftech, not even that kid down the street who smells other peoples garbage could mess it up. Okay maybe he could, but I assure you its simple.
The noise generated by water cooling is little. Fans are required for one (or maybe two) thing(s) only: the radiator must stay cool somehow. You want a fan on it to do just that. And if youre smart, youll slap another fan in that case to expell ambient heat.
But the temps, oooh the temps. So safe... so low.
I know what youre thinking... "too good to be true" or "wheres the catch?" right? Smart kid.
The downfalls of water cooling:
Price: A retard-proof kit can cost a pretty penny. A DIY kit can run at a decent price, but its nowhere near the $60-80 youll pay for 5 nice case fans and a quality hsf.
Upkeep/Setup: Putting one together can be a chore. With everything from assembly to bleeding to wetting agents to clouding, it can become tiresome. A keen eye has to be kept on the system to ensure you arent throwing your $200 cooling investment down the drain... heehee.
Man, in the end all I can say is- its a matter of taste. But any kit that cools properly will require planning, so know how each works and what youll need to do each before you move in for the buy. And youve got the right idea surfing forums before you purchase. Ive researched my new system since November.
As I said earlier, I just ordered parts for a custom build system. Personally? I bought the loudest, fastest most obnoxious hsf on the market.... and a controller panel. Sound doesnt bother me, and its nice to know I can control things when I need a little extra "umph" or when I dont whant my case sounding like a damn hair dryer.
Let me also recommend something: drop by this site
and browse around. Their forums
contain a category on extreme cooling
that contains lots of info on WC. Its based out of the UK, but IMO these guys are unparalleled when it comes to knowledge and talent.
And when you come across any product that peaks your interest, google a few reviews on it and read what the pros/users have to say about it.
If I had some info as to what you were looking to spend/buy and a shopping list, I could suggest some things. If you have AIM Id be happy to talk it out with you. Screen name is the same as mine here.
Hope his helps.