jay, 2 main things you need to keep in mind. The bigger one is a magical number of 3000 CFM. Whatever fans you get, you need to have a total air flow of atleast 3,000 CFM. Getting less can lead to overheats in adverse weather (ie, 100+F days).
The second thing to keep in mind is the style of controller you use. Controllers come in 3 flavors. You have a wire wound controller that will switch on the fans. It is a purely mechanical switch. Very cheap, but also tends to lead to all sorts of issues because the wound wire portion is exposed to the environment and if you get any corrosion on that wire, things go downhill really fast.
The second style is the basic ON/OFF relay with an associated relay for handling of the high current portion of the circuit. For the money, these are about as good as you are going to get while keeping things reliable (still running on my original one 10 years ago). You can normally tell these as they are a little box with a relay mounted on the side and have a small electronic adjustment on the side.
The final style are the PWM controllers. These have a tendency to look like a small car amp. They use pulse width modulation. Pulse what? Precisely. It is fancy talk for turning the fans on/off really fast and letting the momentum of the fan carry it when the fan is off. This is all done electronically. These are nice since you don't get quite the temperature spikes that an on/off setup may cause and you also get a lot of adjustments that you can play with. The con is, you have a lot of adjustments that you can play with and the associated price. You also have to figure out where to place the PWM box. Some are larger than others, but you still have to figure that out. There's tons of room in front of the radiator, but now you have to figure out how you are going to run the wiring from behind the radiator to infront of the radiator and then back to behind the radiator. It can be done, but things are easier if you can keep it all behind.
When it comes to the wire, I would need to know the current draw of the fans before I start just whipping out wire sizes that I would recommend. Also, rough ideas of where you plan on mounting things. In some cases, a certain gauge wire is good for a short run, but not for a longer run.
