When you buy a radiator you get only the radiator so you would need suitable fans in addition. It is usually cheaper to go for the kit and top it off with couple of additional parts than getting all the same parts separately. These alphacool kits are very
decent overall. What I like most is that they are using their full copper core radiators in their kits which have damn solid performance for the radiators of that size. The industry standard is using brass for the radiator cores, which is a bit cheaper and lighter usually, but brass has also a bit less thermal conductivity. The other components seem to be pretty reasonable quality as well. They even have compression fittings in most of their kits, which, when bought separately can and usually do add up cost damn fast.
And now that you mention it ... it seems indeed that for some reason Aquatuning is out of stock for practically everything. I think it happened during the last weekend - I'm expecting them to ship me couple of GPU core blocks shortly myself - I would write to them and ask whats up if you have found something suitable for your purposes from their site. Might be some kind of electronic database problem as I find it highly unlikely that they would go out of stock of practically everything overnight.
As far as I have seen they have also very reasonable shipping costs although if ordering internationally the reasonable cost shipping options tend to be a bit on the slow side taking up to few weeks to reach you.
Edit: I personally prefer stuff separately. I.e., radiator, pump, res, etc on their own. Well ok Res/pump combos are ok buty getting everything in one unit I would avoid unless you are critically tight space wise. Makes it easier to upgrade down the road if you can switch out components individually.
Edit2: Actually now that I think about it - I think they had a birthday party planned for roughly to the current time and there was supposed to be a big sale on that event, so it's possible they have just unlisted everything from their stock for the duration when the items are out at the party and on sale physically. It happens in Germany tho, so not that useful for you in the US part of the world or for me ~1200 km to the northeast of them Edited by Carniflex - 8/17/12 at 2:18am